WPS Development for Non-Welding Engineers - Jan 2021

Welding Answers
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This publication or any part thereof must not be reproduced in any form without the written
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The information presented in this publication is for general information only. While it is believed
to be accurate, this information should not be used for any specific application without
competent professional examination and verification of its accuracy, suitability and applicability
by a licensed professional engineer or designer.
Printed in the United States of America
First Printing: January 2021
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LEGAL DISCLAIMER
THERE ARE NO WARRANTIES SET FORTH IN THIS AGREEMENT, THESE MATERIALS ARE TO PROVIDE
GENERAL INFORMATION. THE AUTHOR MAKES NO WARRANTY WHATSOEVER REGARDING THE GOODS,
SERVICES, OR PROCEDURES, INCLUDING ANY (1) WARRANTY OF MERCHANTABILITY; (2) WARRANTY OF
FITNESS FOR A PARTICULAR PURPOSE; (3) WARRANTY OF TITLE; OR (4) WARRANTY AGAINST
INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OF A THIRD PARTY; WHETHER ARISING BY LAW,
COURSE OF DEALING, COURSE OF PERFORMANCE, USAGE OF TRADE, OR OTHERWISE. BUYER
ACKNOWLEDGES THAT IT HAS NOT RELIED ON ANY REPRESENTATION OR WARRANTY MADE BY SELLER,
OR ANY OTHER PERSON ON SELLER’S BEHALF. BUYER FURTHER ACKNOWLEDGES THAT IT MUST
FOLLOW STRUCTURAL WELDING CODES, PROPERLY QUALIFIED WELDING PROCEDURES, STATE OR
FEDERAL SAFETY STANDARDS, OR OTHER REQUIREMENTS BY LAW, AND NOTHING IN THIS DOCUMENT
SHALL SUPERSEDE THE SAME. BUYER ASSUMES FULL RESPONSIBILITY FOR COMPLIANCE WITH THE
APPLICABLE WELDING CODES OR OTHER WELDING STANDARDS AND IS STRONGLY ENCOURAGED TO
REFER TO GUIDELINES, ASSURE THE FABRICATOR HAS SKILLS NECESSARY FOR THE JOB, AND
CONDUCT ANY TESTING NECESSARY TO CONFIRM THE COMPLETENESS OF THE PROCEDURE,
AMENDING DUE TO CIRCUMSTANCES AND WHERE NECESSARY. THE FUNCTIONING AND USE OF ANY
WELDING MATERIALS IS ENTIRELY DEPENDENT ON THE KNOWLEDGE, SKILL, AND TRAINING OF THE
INDIVIDUAL USING THE MATERIALS
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WELDING PROCEDURE DEVELOPMENT FOR
NON-WELDING ENGINEERS
A step-by-step guide followed by welding engineers of all skill levels in developing
welding procedure specifications
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TABLE OF CONTENTS
How to use this guide
Introduction
Who Should Develop Welding Procedures
Contract Documents
Quality Standards
Developing a Welding Procedure Specification
1. Welding Procedure Information
2. Selecting the best welding process
2.1. Available equipment
2.2. Joint type and welding position
2.3. Indoor/Outdoor
2.4. Welder skill
2.5. Quality and acceptance criteria
2.6. Productivity
2.7. Return on investment
3. Process type
4. Joint design
5. Base metal considerations
5.1. Weldability
5.2. Supplied condition of base metal
5.3. Manufacturer’s recommendation for welding
5.4. Base metal chemistry
5.5. Base metal surface conditions
6. Selecting the right filler metals
6.1. Matching strength
6.2. Undermatching strength
6.3. Expected service conditions
6.4. Stress relieving applications
6.5. Hardfacing applications
7. Selecting the right shielding or flux
7.1. Shielding gases
7.2. Effects of shielding gases
7.3. Submerged arc fluxes
7.4. Selecting the right wire/flux combination
8. Welding position
9. Electrical characteristics
9.1. Short circuit transfer
9.2. Globular transfer
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9.3. Spray transfer
9.4. Pulsed spray transfer
10. Technique
10.1. Stringer versus weave
10.2. Single versus multipass
10.3. Contact tip to work distance
10.4. Peening
10.5. Interpass cleaning
11. Preheat and interpass temperature
11.1. Determining if preheat is necessary
11.2. Determining preheat and interpass temperature
11.3. Preheat and interpass temperature for structural steels
11.4. Taking preheat and interpass temperature readings
12. Post weld heat treatment
12.1. Postheating
12.2. Stress relieving
13. Welding procedure (operating parameters)
13.1. Effect of welding variables on productivity
13.2. Effects of welding variables on quality
13.3. Testing of welding procedures
13.4. Using prequalified welding procedures
13.5. Selecting welding parameters
13.5.1. Amperage (current)
13.5.2. Voltage
13.5.3. Travel speed
13.5.4. Travel angle
13.5.5. Transverse angle
13.5.6. Contact tip to work distance
14. Additional requirements
Final Remarks
References
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HOW TO USE THIS GUIDE
This guide provides the user a step-by-step process to follow to develop a welding procedure
specification (WPS). This is the same process used by many accomplished welding engineers.
A WPS is an engineering document and must be treated as such. Your choices for all the
different variables will have an impact on both quality and productivity and thus must be
approached methodically.
In Figure I.2 you’ll see a sample WPS split up into the sections numbered 1 - 14. Depending on
your function, you may not need to select values for all of these sections. For instance, if you
are building a product for a customer that has provided the design documents and already
specified base materials and joint design you may not need to do anything other than specify
the base materials in your WPS. However, you will still need to develop a procedure and
choose filler metals, shielding gases, determine whether preheat and post weld heat treatment
are required, and many other choices that will impact quality and productivity.
These sections are arranged in a specific order; however, it is not imperative that you follow that
order. If you are only concerned with whether preheat is necessary you could jump straight to
section 11.
This guide focuses on carbon and low alloy steels, but the same methodology may be used for
other base metals. The principles are the same.
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INTRODUCTION
When tasked with developing a welding procedure specification (WPS) we typically lean
towards using a welding process and a filler metal with which we are familiar. Then, we proceed
to selecting adequate amperage and voltage and this is where most “welding procedure
development” stops. The development of a WPS is much more involved than selecting a wire
feed speed (or amperage), voltage and filler metal. Unfortunately, this simplistic approach is all
too common when welding carbon steels.
A lot of failures occur because fabricators incorrectly assume that the welding procedure
followed for a specific carbon steel will work on all others. This leads to welding defects and
failures which could have been avoided with a properly developed WPS.
Another concern with welding procedures is productivity. Most fabricators are concerned with
this, but the tendency to stick with what’s familiar ends up costing them a lot of money. Of
course, these fabricators realize they are leaving money on the table. Many times they don’t
realize that improvements to the WPS could make them more productive.
This publication was written to give the reader a process to follow to develop WPSs. It takes
everything into account including special items such as determining whether preheat is required,
when post weld heat treatment is necessary, how to evaluate different arc welding processes in
terms of quality and productivity and, perhaps most importantly, the effects of the essential
welding variables and how to select them (amperage, voltage, travel speed, shielding gas/flux,
filler metal, filler metal diameter, etc.). It addresses these choices with both quality and
productivity in mind.
WPSs, along with procedure qualification records (PQRs) and welder performance qualification
records (WPQRs), are the foundation of a sound welding quality control program. A welding
procedure does not only impact the quality of a weld but also productivity and thus cost.
When welding procedures are required, they are typically developed in order to pass the
acceptance criteria of the code or standard to which they must conform. This is done in order
to satisfy a customer’s requirement and it is typically done on an as-needed basis. The vast
majority of manufacturers will not develop and qualify welding procedures if a job does not
require it. This is done to save money. Why spend time and resources qualifying welding
procedures if they are not required? As you go through this publication, you’ll learn that
developing and qualifying WPSs for all your work will allow you to improve quality and improve
productivity. This in turn, will lower your manufacturing costs.
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WHO SHOULD DEVELOP WELDING PROCEDURES
Developing a welding procedure is the responsibility of the welding engineer. Most fabricators
don’t have a welding engineer on staff and require that those with the most welding knowledge
develop the WPS. Many times this falls in the hands of the certified welding inspector (CWI).
This is not a bad thing, after all, CWIs are trained on interpreting and applying welding codes.
However, keep in mind that a CWI may have sufficient knowledge of welding processes and
may have experience writing procedures, but a CWI certification does not guarantee this.
A CWI may easily create WPSs for steel structures since the code (i.e. AWS D1.1) provides a
lot of guidance. AWS D1.1 will tell the user what steels are covered under the code, what the
matching filler metals are for each of these steels, whether or not preheat is required, special
considerations for specific steels such as quenched and tempered steels, and much more. But
what happens if you have a base metal not covered by the code? What filler metal should you
use? Should you be concerned about excessive heat input and its effects on mechanical
properties? Should you be concerned about corrosion or other problems that cannot be
detected through normal inspection?
Developing a WPS for materials that are not covered by a code or that are highly sensitive to
cracking or other defects is a serious matter. Even accomplished welding engineers struggle
with this. Not many welding professionals are able to develop a sound WPS without assistance.
This assistance may come from colleagues, books, the internet, the manufacturer of the base
material, the manufacturer of the filler metal or other industry experts.
What welding engineers that develop WPSs do well is they know what questions to ask. They
have a process to follow in order to develop a welding procedure. They use this process
whether they are welding ASTM A36 steel, super duplex stainless steels, cast iron, aluminum,
galvanized steel, or any other material. They never make the assumption that the welding
procedure that worked on one base metal will work on another.
Just like a CWI knows how to use welding codes and knows where to find answers, so does a
welding engineer when it comes to developing welding procedures. A problem in our industry is
that we have a tremendous shortage of welding professionals. This includes welders, fitters,
cutters, inspectors, technicians, supervisors and welding engineers to name a few.
This means that the responsibility to develop a welding procedure can land on anyone,
regardless of their work experience, schooling or background. And this can be a daunting task
giving the implication of writing a welding procedure. The good news is that with a bit of welding
experience, proper instruction and basic knowledge of welding processes anyone can write a
welding procedure as long as a proven process is followed.
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This guide is meant to provide the non-welding engineer with a process to develop welding
procedure specifications for any base material. The focus is on structural steels, but the
principles apply to any base material.
So where do we start?
In order to develop a good WPS you must understand the application, what code or standard (if
any) needs to be followed and any special requirements imposed by your customer. Depending
on the specific industry and the size of the job you may be presented with contract documents
by your customer. If these documents are present this is where we start.
CONTRACT DOCUMENTS
Contract Documents are codes, specifications, drawings, or additional requirements that are
contractually specified by the owner. The owner being the individual or company that exercises
legal ownership of the product or structural assembly produced to a certain code or standard.
Whenever contract documents are available you must determine if there are any specific
instructions pertaining to welding. And more importantly, find out if there are any specific
requirements pertaining to welding processes, filler metals, welding procedures, need for
qualification of welders and procedures, etc. Many times the contract documents will tell you all
you need to do and may even supply qualified welding procedures.
When contract documents specify a welding code or standard to follow you must have a copy of
said standard and be able to read it and interpret it. Because welding codes are used
extensively you will see contract documents call them out frequently. Some contract documents
will simply state “​...all welding shall be done in accordance with AWS D1.1 Structural Welding
Code - Steel​” or whatever other code is specific to the project. This is good, as these codes
provide instructions for qualification of welding procedures, qualification of welders, fabrication
practices and inspection procedures. However, none of the codes will actually provide welding
procedures.
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Figure I.1 ​- AWS structural welding codes are often specified in contract documents as the quality standard to follow.
These codes provide detailed instructions for the qualification of welding procedures and welder performance. These
are two of the most important components of a sound quality control program.
Some codes allow the use of prequalified welding procedures which means you can use a
procedure as “qualified” without the need to conduct any kind of testing. But you still have to
develop the procedure yourself and knowledge of how to do this is critical. Prequalified WPSs
require you to comply with strict code requirements which require deep knowledge of these
welding codes.
If contract documents are not provided by the customer what do you do? This is often the case,
especially for smaller projects. If no contract documents are provided, there must still be quality
standards that you adhere to.
QUALITY STANDARDS
When contract documents are not available you may still receive a welding quality standard
from your customer. These welding standards or welding guidelines will not contain welding
procedures. However, these guidelines often provide the acceptance criteria for all welds and
may suggest or mandate that you follow specific welding procedures which must be developed
following certain published standards.
Other times your customer will simply tell you what to build for them. They will provide prints and
no additional guidelines. In these cases you will default to your own internal quality standards.
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Lastly, if you do not have internal quality standards you should use a welding code that covers
the materials you are going to be welding. For example, if you will be fabricating stainless steel
structures you are advised to use AWS D1.6 Structural Welding Code - Stainless Steel as your
quality standard.
Regardless of whether or not you are provided contract documents or a quality standard to
follow, you will typically need to develop and qualify your own WPSs. A good welding procedure
is not just one that can weld two members together without defects, but also one that can
achieve this at the lowest possible cost. Bear in mind that this does not mean compromising
quality. You can have both quality and high productivity with a properly developed welding
procedure.
DEVELOPING A WELDING PROCEDURE SPECIFICATION
The following steps are followed by welding engineers and other welding industry professionals
in developing WPSs. Most people in charge of developing procedures consider both quality
(meeting requirements imposed by a code, standard or other documents) and productivity.
However, many times only the quality aspect is considered and the developer of the WPS
inadvertently increases costs significantly for the fabricator. If you carefully follow the process
outlined below you will be well on your way to developing a quality procedure that maximizes
productivity and lowers cost.
Figure I.2 on the following page shows a sample Welding Procedure Specification. There are a
total of 14 sections which are contained in numbered and individual boxes. These numbers
correspond to the sections on this publication.
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Figure I.2​ - Section of a Welding Procedure Specification.

1. WELDING PROCEDURE INFORMATION
All welding procedures must have a welding procedure specification number (WPS No.).
A supporting procedure qualification record (PQR) must also be specified. This is the
PQR from which the WPS was written. The PQR is the document that shows test results
as well as all the welding variables that were used for the qualification of the WPS.
If the procedure is prequalified then no PQR number is necessary, simply state that the
welding procedure has been prequalified in accordance with the governing code.
All welding procedures, whether prequalified or qualified by testing, must be approved by
the company that will use them. The date in which it was approved must be noted as
well as any revisions.
Properly documenting a WPS is extremely important. Make sure that this header section
is always filled out properly. Revisions to the WPS must be noted along with the
corresponding date.
2. SELECTING THE BEST WELDING PROCESS
Selecting the best welding process is a critical step in developing a welding procedure
that attains the desired quality and optimizes productivity. Many times we look for the
welding process that can give us the highest deposition rate to optimize productivity.
However, every welding process has limitations. For example, submerged arc welding
(SAW) has extremely high deposition rates, but it is limited to the flat and horizontal
positions, it is not feasible for short welds and it requires the use of flux which adds
complexity to the process. So it may not always be the best option.
Following are the most important factors to consider when selecting the best process.
These are not listed in any particular order.
2.1. Available Equipment
In the vast majority of cases the determinant factor in selecting a welding process is the
equipment that the fabricator has available. This makes perfect sense, but you must
always consider other processes. There are times when purchasing new welding
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equipment can lower the total cost of the project by increasing productivity and quality
(less rework).
2.2. Joint Type and Welding Position
There are 5 types of joints: Tee, butt, corner, edge and lap. Certain joint types lend
themselves better to certain processes. For example, SAW can be used in butt and tee
joints, but not really feasible for most edge, lap and corner joints.
Figure 2.1​ - Joint Types
The welding position (flat, horizontal, overhead or vertical) further narrows down the
processes which may be used. If you have a butt joint that is in the vertical position it
would render SAW useless. All other processes are still options, but then you can look
at deposition rates for out of position welding. Typically, processes that produce slag
(FCAW and SMAW) are good options for out-of-position welding. GMAW and GTAW
may be used but they would most likely result in lower deposition rates.
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Figure 2.2 ​ - Welding positions by weld type
2.3. Indoor/Outdoor
Whether welding is being carried out indoors or outdoors may also dictate which welding
process we use. Any process may be used outdoors provided proper shielding from the
elements is provided; however, this isn’t always practical.
Figure 2.3 - The Albion Canal bridge is seen here covered by a huge canvas in order to undergo
construction. These canvases allow for the use of gas-shielded welding processes as they block
the wind. In the winter months in cold climates these covers also permit the use of heat in order to
maintain an ambient temperature in the vicinity of the weld which would still permit welding.
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The best processes for welding outdoors are stick (SMAW) and self-shielded flux-cored
(FCAW-S). These processes can handle winds of up to 35 mph [56 kph] without
experiencing negative effects. If you need to use GMAW, FCAW-G or GTAW outdoors
you would need to have barriers that block the wind as shown above in Figure 2.3. Even
a 5mph [8kph] draft is enough to cause porosity by blowing the shielding gas away when
using gas-shielded welding processes.
2.4. Welder Skill
The skill level of the welders is another important factor. Certain processes such as
GTAW and SMAW require a higher level of welder skill as compared to the GMAW and
FCAW. SAW is done automatically in which case the welder skill may not be overly
important as this person is a machine operator rather than a welder. Furthermore, all
processes can be automated by the use of robots or hard automation. In this case,
welder skill is not as critical of a factor.
2.5. Quality and Acceptance Criteria
Certain processes are better than others at obtaining certain levels of quality. If products
need to be x-rayed it may be more beneficial to use a process without slag. However,
x-ray quality welds may be attained with all processes. The joint type comes into play
here as well. For example, in a 45-degree included angle for a groove weld butt joint
SAW may be a great option. If the bevel is then decreased to 25-degrees SAW, or other
slag-producing welding processes may generate slag inclusions. In this case you may
want to consider a process that does not produce slag, such as GMAW.
Some welding processes may achieve deeper penetration than others. In some cases
this is important since certain welds may require a specific amount of penetration.
Processes that provide deeper penetration may reduce costs by not having much joint
preparation, such as beveling, in order to achieve the desired results. They may also
allow the user to reduce the root opening which in turn would reduce weld volume.
2.6. Productivity
Productivity is one of the most important factors which must be considered when
developing a WPS. The deposition rate of the different arc welding process should be
taken into consideration. But keep in mind that welding speed alone is not all you need
to take into account. Processes that produce slag require clean up and also have a
lower electrode efficiency as is the case with FCAW and SMAW.
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Below are typical deposition rates of arc welding processes. These ranges are what’s
considered practical. We could certainly deposit 20 lb/hr with the GMAW process but it
would not be practical.
GTAW → 0.5 to 4 lb/hr
SMAW → 1.0 to 7.0 lb/hr
FCAW-SS → 4.0 to 12 lb/hr
FCAW-GS → 4.0 to 15 lb/hr
GMAW → 2.5 to 15 lb/hr
MCAW → 4.0 to 15 lb/hr
SAW → 12 to 35 lb/hr
2.7. Return on Investment (ROI)
Once we understand the productivity factors of each process we can run a return on
investment calculation. This can include the purchase of new equipment. If we determine
that SAW is the most productive process we may consider buying the equipment if we
don’t already have it. A SAW system can run between $20,000 and $80,000. You will
need to determine if the investment has a rate of return that is acceptable to your
company.
3. PROCESS TYPE (LEVEL OF AUTOMATION)
The options for this section of the WPS are: manual, semi-automatic, automatic or
mechanized.
The welding process dictates the types of welding (level of automation). SMAW is a
manual process. A welder holds the electrode holder and manually feeds the electrode
during the welding process. GTAW is also a manual welding process.
Welding processes that have a wire feeder such as FCAW, MCAW and GMAW are
semi-automatic processes if they are being used by a welder. These processes become
automatic if they are used on a robot or mechanized if used with hard automation.
SAW is almost always a mechanized process. Although very rare, there is handheld
SAW. In this case, the process would be semi-automatic.
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Just as in selecting the right welding process, selecting the level of automation should
not be limited to the equipment that is currently available. Automation can help increase
productivity and quality, but a proper return on investment analysis should be carried out.
4. JOINT DESIGN
The joint design is something that we typically have very little control over when
developing a welding procedure. The determination of whether a weld should be a CJP,
PJP or fillet weld is the responsibility of the design engineer. However, there are times
when we have the option of choosing the weld type or, at the very least, the joint details.
An example of this would be the following. Suppose in part of a shop drawing we see
something like this:
Figure 4.1​ - Welding symbol calling for a complete joint penetration weld on a butt joint.
If a drawing calls for a CJP weld as shown above, you have the option of selecting the
joint details. This means you can choose to weld from one side or from both sides. You
decide what kind of joint preparation will be used. This means you decide if you want to
bevel one or both plates, the degree of the bevel, whether or not you need an open root
or use a backing bar (temporary or permanent), etc.
The joint details that you select can significantly impact the cost of fabrication. For
example, if you choose to weld from one side by using a v-groove you would use more
weld metal than if you welded from both sides with a double v-groove. However, if you
weld from both sides you would more than likely have additional operations -
manipulating the part (flipping it) and backgouging, but you would use less weld metal.
Sometimes the choice of joint details is dictated by the welding code you are following. If
you intend to use prequalified welding procedures then you must use a prequalified joint
and adhere to the specified tolerances.
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Figure 4.2 ​- Prequalified joint details for a double v-groove weld per AWS D1.1 Structural Welding Code -
Steel
Prequalified welding procedures are permitted by certain structural welding codes such
as AWS D1.1 (Steel), AWS D1.3 (Sheet Steel) and AWS D1.6 (Stainless Steel). These
codes provide prequalified joint details including tolerances. Using these joints provide
the advantage of knowing that sound welds will be obtained provided a good welding
procedure is in place. The potential downside is cost. Prequalified welding procedures
don’t require testing, which saves you time and money. But changing joint details to
values not permitted when using prequalified welding procedures may be advantageous.
You may be able to significantly reduce weld volume by having a tighter groove.
Because it is not a prequalified joint you will incur additional costs in testing, but your
welding time may be reduced and actually save you money.
The use of backing for CJP welds may also be an option. Keep in mind that if your
fabricated product will be subject to fatigue loading the backing plate must be removed
after welding.
Backgouging is required in prequalified WPSs for CJP welds which are double sided.
Backgouging can only be omitted if the welding procedure is qualified by testing.
However, most double-sided CJP welds should be backgouged to ensure 100%
penetration and no inclusions.
As you can see a lot goes into selecting the right joint details.
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5. BASE METAL CONSIDERATIONS
Most likely you don't have the option of changing the base metal when developing a
welding procedure. Therefore, you must understand any special requirements of the
base metal or base metals you will be welding.
Some base metals require the use of preheat in order to avoid cold cracking (hydrogen
induced cracking). Sometimes the use of preheat has to do with the thickness of the
base metal rather than the composition.
The WPS should state what base metal you are welding, or what base metal group if
required by the governing code. Most welding codes will place base metal into groups in
order to reduce the number of welding procedure qualification tests and welding
procedure specifications needed. For example, AWS D1.1 Structural Welding Code -
Steel groups base metals into Group I, II, III and Unlisted Metals.
The following aspects of the base metal or metals you’ll be welding must be fully
understood in order to develop a sound welding procedure.
5.1. Weldability
Weldability does not simply refer to whether or not a metal can be joined by welding.
This term, unfortunately, is interpreted to mean many different things. However, the
weldability of a base metal describes both the ability to successfully fabricate a
component using welding and the capacity for that component to perform adequately in
its intended service environment.
To illustrate weldability think of welding cast iron. Cast iron is weldable because it can
be joined by welding. However, it has poor weldability because it is extremely crack
sensitive. Understanding the weldability of the base metal is key in developing the right
welding procedure. Remember, a welding procedure is not simply selecting a welding
process and parameters such as amperage and voltage. It may involve preheating, post
weld heat treatment, specific welding sequences, specific bead placement, etc.
It is imperative that you have a thorough understanding of the chemistry of the base
metal you are welding, how it is affected by the heating and cooling cycles induced by
welding, and what the service conditions of the fabricated product will be.
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5.2. Supplied Condition of Base Metal
A base metal may have different levels of weldability depending on which condition it is
supplied. That is, annealed, normalized, quenched and/or tempered.
When steel is hot worked or cold worked during the manufacturing and forming
processes, residual stresses are introduced in the steel. These residual stresses may
not allow the steel to perform as intended. In order to attain the right levels of hardness,
ductility and toughness the steel must undergo heat treatment to relieve internal stresses
and to attain the desired mechanical properties.
The most common heat treatments are: annealing, normalizing, quenching, and
tempering. The heat treatment performed will determine the condition of the steel you
will receive and will affect its weldability.
Annealing involves heating the steel in a furnace to a temperature 100F [38C] above
the critical temperature. This temperature is then held for a certain amount of time to
allow the carbon to dissolve and diffuse throughout the metal. The steel is then allowed
to cool slowly inside of the furnace at a controlled rate. Annealing helps refine the grain
structure of the steel and make it more ductile. It also gets rid of most residual stresses,
resulting in excellent weldability.
Normalizing ​involves heating the steel at a temperature above the annealing
temperature and then taking it out of the furnace and letting it cool in air. The result is an
increase in hardness and strength when compared to annealing. Normalized carbon
and low alloyed steel will be less ductile than when annealed. Normalized steel also has
excellent weldability.
Quenching involves the rapid cooling of steel in air, water or oil. Typically it is done in
either water or oil. Oil provides slower cooling than water but it is very useful because it
can prevent quenching cracks. Steel that will undergo quenching is typically medium
carbon and alloyed steel. The result is very high hardness and strength, but this comes
at the expense of ductility. Quenched steels are very brittle and very crack sensitive
when it comes to welding. They also tend to have residual stresses that make welding
even more complicated. It is not advisable to weld a quenched steel because they are
highly susceptible to cracking.
Tempering is done after quenching in order to regain some ductility and eliminate
residual stresses. Tempering is done by reheating the steel after the quenching process
and allowing it to cool slowly in air. Hardness is reduced and the residual stresses are
eliminated. The reheating temperature depends on the material type. Quenched and
tempered steels have medium weldability. They can successfully be welded without
problems but the welding procedure must be properly developed and tightly controlled. It
is also important to know that welding will change the mechanical properties of the base
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metal in the heat affected zone. This may require additional heat treatment to restore the
quenched and tempered properties.
Steel supplied in the annealed or normalized condition will typically have excellent
weldability. This means it is not very crack sensitive, but care must still be taken. Steel
can also be supplied in the quenched and tempered (Q&T) or hardened and tempered
(HT) condition. Welding in the Q&T or HT condition is not recommended. The high
strength and hardness coupled with low ductility of the base metal will have significantly
different expansion and contraction rates than the weld metal. This may result in very
high residual stress which may end up causing cracks.
If Q&T steels have to be welded, it is very important to follow proper preheat and
interpass temperatures as well as understand what kind of postweld heat treatment
(PWHT) may be necessary.
It is recommended that Q&T steels be annealed prior to welding to prevent cracking.
Then, to regain the Q&T properties, the proper PWHT must be applied.
5.3. Manufacturer’s Recommendations for Welding
If you are welding commonly used carbon steels such as ASTM A36 you may not need
much information since we know it has great weldability. But what happens when we
have to weld on high strength steel or abrasion resistant plate?
The manufacturer of the metal you will be welding should have recommendations for
welding, especially if the material is supplied in any form other than annealed or
normalized. Some manufacturers will have very detailed welding guides. Arcerlor Mittal
is a perfect example of a manufacturer that provides detailed instructions on how to weld
their products.
It is not always possible to know the manufacturer of the base metal, but the supplier
(distributor) of the steel may have information that was provided to them by the
manufacturer. This will not have the detail that welding guides like the one in Figure 5.1
provide, but at least it lets you know certain items to consider.
23

Figure 5.1 - Arcelor Mittal publishes guides on how to weld several of the steels they manufacture.
These guides contain information that must be considered when developing a welding procedure.
Figure 5.2 below shows what you’ll typically find from a steel supplier.
Figure 5.2 ​- Information provided by a steel supplier for the weldability of ASTM A572 Grade 50
steel.
24

In this case we are not given much information other than the base metal is easily
weldable. This is a good sign, but care must still be taken. If you don’t see a section for
weldability or if the information says the base metal is not easily weldable don’t assume
it can’t be welded. Look at the chemistry and make your own evaluation. Also, if you
are unsure about weldability you can always run qualification tests to prove out the
procedure.
5.4. Base Metal Chemistry
Knowing the chemical makeup of the material you are welding is very important. When
dealing with carbon steels we need to know how much carbon is contained in the steel.
This will allow us to make determinations as to whether or not preheat is required,
whether or not we need to be concerned by the heat input from the welding process,
whether or not the weld and heat affected zone will be susceptible to hydrogen-induced
cracking, etc. It is also important to know if it contains tramp elements that could
potentially cause issues such as porosity, solidification cracking and other problems.
A material test report (MTR) is always available from the manufacturer of the steel. If
you are dealing with a base metal that is new to you, always study the MTR.
When you start getting into nickel-based alloys and aluminum alloys the chemistry
becomes even more important. Selecting the wrong filler metal can cause welding
defects such as solidification cracking. It can also produce corrosion resistance levels
below what may be required.
5.5. Base Metal Thickness
The thickness of the material you are welding is an important factor in determining the
right welding process to use. It is also important when determining if preheat may be
necessary. Preheating is used primarily to slow the cooling rate after welding. This is
important to prevent the formation of martensite in the weld and heat affected zone.
Martensite is a hard and brittle microstructure which is susceptible to hydrogen-induced
cracking.
The thicker the material the quicker it will cool after welding. Certain steels, such as
ASTM A36 do not require preheat unless the thickness exceeds ¾ inch [20 mm]. Other
steels require preheat because of the high carbon content regardless of thickness. The
higher the carbon content the higher the susceptibility to cracking due to the base
metal’s susceptibility to be hardened.
25

In some cases we want high strength, high hardness and low ductility for specific service
conditions. However, this is seldom the case with a weld.
5.6. Base Metal Surface Conditions
The surface condition of the base metal you will be welding may vary significantly. It
may be clean one day and have excessive amounts of cutting fluid or oil the next. It may
have a heavy mill scale. In the case of steels with coatings, such as galvanized steel,
the thickness of the coating may vary. All these variables affect the quality of the weld.
A properly written welding procedure will address these issues. It may do so simply by
ensuring the parameters selected are enough to weld through all those impurities and
other surface abnormalities or it may call for proper cleaning prior to welding. Don’t think
that the heat of the welding arc is enough to burn through surface contaminants, this is
not always the case.
6. SELECTING THE RIGHT FILLER METALS
Selecting the filler metal should not be a trivial matter. The easy way out is to select a
filler metal that has matching strength, meaning that the minimum specified tensile
strength of the filler metal matches that of the base metal. However, this is not always
the best option. In some cases it may be beneficial to use undermatching filler metals.
There are many factors to consider when selecting the right filler metal. Understanding
requirements in the areas of strength, ductility, wear resistance, corrosion resistance,
in-service demands, cost and productivity is essential.
Below are aspects that must be taken into consideration when selecting a filler metal for
the welding procedure being developed.
6.1. Matching Strength
The American Welding Society does not formally define the term “matching strength.”
However, what is accepted in the industry is that matching strength simply means that
the filler metal’s minimum specified tensile strength will be equal to or greater than that
of the base metal. Determining whether or not matching strength is required depends on
the type of joint being welded and the loading conditions experienced in service.
Typically, matching strength is required in complete joint penetration (CJP) groove welds
26

in tension applications.
choice.
However, it is not always the most conservative or economical
Codes will sometimes provide matching filler metals. For example, in AWS D1.1
Structural Welding Code - Steel, you will find in the Prequalification clause (Clause 5 in
the latest edition - 2020) matching filler metals. If the code recommends a particular
filler metal you must not immediately assume it is the best choice. Understanding the
requirements of the weld is important as using an undermatching filler metal may be
advantageous.
6.2. Undermatching Strength
Rather than focusing on when to use matching filler metals our focus should be on when
to use undermatching filler metals. This may sound like a bad idea to some. Why would
we want to use a filler metal that is weaker (in terms of tensile strength) than the base
metal? The answer is: when the welded connection can benefit from it. As tensile
strength of base metals and filler metals goes up ductility goes down. This means that in
highly restrained joints the probability of cracking goes up. If we use an undermatching
filler metal the weld will have higher ductility and will be better able to handle residual
stresses without cracking. Whenever you are welding high strength steel, consider the
use of undermatching filler metal on fillet welds and partial joint penetration (PJP) welds.
In many of these cases, especially fillet welds, we can use undermatching filler metals
without having to increase the weld size. Other times, when the weld is transferring all of
the stress we can still use undermatching filler metals and simply increase the size of the
weld. This would require more filler metal and more welding time than if we used a
matching strength filler metal, but by using an undermatching filler metal we eliminate or
reduce cracking susceptibility which in the long run will save us a lot of money.
The same can be said of PJP welds. The weld can be made bigger to compensate for
the strength required but still have higher ductility than if a matching filler metal was
used.
Welding engineers must understand the design concerns of using matching and
undermatching filler metal. For most structural steels using matching filler metal is a
safe option. However, once you start getting into high strength steels consider the use
of undermatching filler metals.
27

6.3. Expected Service Conditions
Understanding the in-service conditions and requirements of the weld, such as service
temperature, exposure to corrosive elements, exposure to wear and impact, and other
factors is very important in selecting the right filler metal.
An example of this is the use of weathering steels. Weathering steels ​are alloyed with
copper, nickel and chromium. These elements provide the necessary atmospheric
corrosion resistance by facilitating the formation of a protective layer of rust which does
not penetrate the surface of the steel.
A matching filler metal for ASTM A588 (a weathering steel) would be one with a
minimum specified tensile strength of 70ksi. However, this particular application requires
a filler metal that will also provide the same atmospheric resistance. In this case, the
use of a wire containing at least 1% nickel is required. In the case of GMAW an
ER80S-Ni1 would be a good option. When multiple passes are required, a filler metal
that closely matches the base metal may be necessary.
Low temperature service conditions may also require special filler metals. When specific
charpy v-notch (notch toughness, or resistance to crack propagation) values are
required, the filler metal to be used may not necessarily be a matching filler metal.
Manufacturers of filler metal will provide this information in their certificates of
conformance. This will let you know if the filler metal being considered will meet the
required notch toughness values.
28

Figure 6.1 - Excerpt from a certificate of conformance for Lincoln Electric’s Super Arc L-56 GMAW filler
metal (ER70S-6) and additional graphs for further explanation. The green oval shows the location of the
toughness values. In this case the test was done at -20F [-29C]. If in-service conditions will be at much
lower temperature a different filler metal may be needed.
A typical requirement may be “50 ft-lb at -40F.” In this case, Super Arc L-56 would not
be an option. It may very well be able to achieve 50 ft-lb at -40F, but the certificate of
conformance does not provide values for toughness at that temperature. At this point
you would have two options: (1) perform a welding procedure qualification tests and test
toughness at -40F, or (2) find a filler metal that has already been tested at -40F and
provides a minimum of 50 ft-lb at that temperature.
6.4. Stress Relieving Applications
Stress relieving is a type of post weld heat treatment which ​is used to reduce residual
stresses that are present after welding. This is done by carefully controlling the heating
of the part to a specific temperature, holding it for a specific amount of time and then
controlling the cooling rate.
29

Stress relieving is also used to reduce distortion and to control dimensional stability and
tolerances.
It is important to know that stress relieving typically reduces weld strength by 10 to 15%.
Therefore, if an electrode classified in the “as-welded” condition is stress relieved, the
final tensile strength could fall below the minimum classification tensile strength.
6.5. Hardfacing Applications
If the in-service application demands resistance to abrasion, impact or other type of
wear, then a filler metal with resistance to these conditions must be selected.
If the weld will experience wear, abrasion or impact, then a filler metal that produces a
specified hardness level must be selected. This hardness level is typically specified
based on the expected type of wear, impact or abrasion.
At times you may be welding abrasion resistant (AR) plates as is typically done with
bulldozer and backhoe buckets. In this case, the weld is just attaching the plate to the
bucket and does not need to have the same abrasion resistance as the AR plate. In
situations like this, the use of undermatching filler metals is recommended.
7. SELECTING THE RIGHT SHIELDING GAS OR FLUX
All arc welding processes require shielding of the molten weld pool from the atmosphere.
In processes like GMAW, MCAW, GTAW and FCAW-G this shielding is provided by
shielding gases such as carbon dioxide, argon, helium or combinations of these which
may also include small amounts of hydrogen, nitrogen and oxygen. In processes like
SMAW and FCAW-S the shielding is still from gases; however, the gas which is
predominately carbon dioxide, is produced by the flux in these electrodes. Thus, no
external shielding gas is needed.
The SAW process gets its shielding by use of flux which is in the form of a powder. The
arc, as the name process name suggests, is submerged in the flux and this is how the
molten weld pool is protected from the atmosphere.
30

7.1. Shielding Gases
Shielding gases do more than provide protection from the atmosphere. They also have
an impact on the following:
●
●
●
●
●
●
●
●
Mechanical properties
Spatter generation
Heat transfer
Welding fume generation
Metal transfer (i.e. short circuit, globular, spray)
Welding speed (ability to get a good wetting at fast travel speeds)
Penetration depth and profile
Bead shape
Selecting an adequate shielding gas for GMAW, MCAW, and FCAW-G does not have to
be complicated. However, with the many different gases available this may become a bit
confusing.
The first place to look would be at what is recommended by the manufacturer of the filler
metal you intend to use. See Figure 7.1 below.
Figure 7.1​ - The manufacturer of SuperArc L-56 recommends several gases which may be used with this
filler metal. These gases are typically listed in the filler metals data sheet as the one seen here.
In this case, Lincoln Electric provides the different shielding gases which may be used
with SuperArc L-56. These gases are carbon dioxide, argon and carbon dioxide mixes
31

with argon content ranging from 75 to 95%, and argon and oxygen mixes with argon
content ranging from 95 to 98%.
This means that there are not just 3 shielding gases, but endless combinations. Below
are a few of the common shielding gas mixtures that would fall within the
recommendations for this filler metal.
➔ 100% CO2
➔ C25 (75%Ar/25%CO2)
➔ C20 (80%Ar/20%CO2)
➔ C15 (85%Ar/15%CO2)
➔ C10 (90%Ar/10%CO2)
➔ C8 (92 Ar/8%CO2)
➔ C5 (95%Ar/5%CO2)
➔ 95/5 (95%Ar/5%O2)
➔ 98/2 (98%Ar/2%O2)
Of course you can have everything in between (i.e. C19, C18, C17 etc.). So with all
these combinations how do you select the right shielding gas? Understanding the
effects the different shielding gases have on the weld is critical. It is important to follow
the guidelines provided by the manufacturer of the filler metal. Also, special care must
be taken when using FCAW electrodes.
FCAW electrodes are tubular wires with flux inside of them. The flux is of a specific
chemistry based on the intended application of the electrode. The flux provides alloying
elements that affect the mechanical properties of the weld.
Inert shielding gases, such as argon and helium, provide shielding from the atmosphere
and are not reactive, meaning they don’t change the mechanical properties of the weld.
Shielding gases such as carbon dioxide and oxygen are reactive and may change the
mechanical properties of the weld metal (compared to the mechanical properties of the
filler metal). In the case of FCAW electrodes, the higher the CO2 content in the
shielding gas the more of the alloy in the flux will be lost due to chemical reactions.
Manufacturers of flux-cored electrodes will specify the shielding gas to use. It is
important to never exceed the maximum recommended percentage of argon. If a
flux-cored wire is designed to run with no more than 75% argon (balance CO2) and the
electrode is used with a C10 (90% argon) mix the weld will exhibit much higher tensile
strength, higher hardness and lower ductility. This can make it susceptible to cracking.
Always use a shielding gas that is recommended by the manufacturer of the filler metal.
See Figure 7.2 below which corresponds to the data sheet for Hobart’s Excel Arc 71
E71T-1 FCAW electrode.
32

Figure 7.2 ​- Manufacturers of FCAW filler metals will specify the maximum amount of argon in argon/CO2
mixes that may be used with the electrode.
Figure 7.2 shows that if you are using FabCo Excel-Arc 71 flux-cored E71T-1 electrodes
you should not exceed 80% argon content in your argon/carbon dioxide mix. If you do,
your welds will be susceptible to cracking due to high hardness and low ductility.
Once you have the list of shielding gases which may be used, you must then ensure that
the shielding gas of choice can provide the required mechanical properties. This is
simply a matter of looking at the certificate of conformance of the filler metal. If the filler
metal was tested with the gas you intend to use and provides at least the minimum
necessary values for mechanical properties, then you can use that gas.
More often than not you will have several shielding gases that provide the necessary
mechanical properties. ​Choosing the right shielding gas ​is a process that must consider
the base metal, base metal conditions, joint type, welding position, material thickness,
and many more requirements.
As stated earlier, you will have many choices. For example, you can weld mild steel with
any of the following shielding gases:
● 100% Carbon Dioxide
● 75% Argon / 25% Carbon Dioxide (75/25)
● 90% Argon / 10% Carbon Dioxide (90/10)
● 95% Argon / 5% Oxygen (95/5)
33

Although all of the above can be used on mild steel you must make your selection based
on the application. If your base material is covered in rust and mill scale then the 95/5
mix is not the best choice because it will not burn through the mill scale and you’ll end up
with lack of fusion. But if we are welding on clean sheet metal then this 95/5 is adequate.
75/25 is an excellent choice for sheet metal as well since it is good with the short circuit
mode of metal transfer, but should not be your preferred choice for welding heavy
sections of steel (for the GMAW process). However, if you use a flux-cored electrode
(FCAW process), then you can use 75/25 without concern for material thickness.
As you can see, there are many considerations when selecting the right gas. The table
below provides general guidelines which may be used when selecting the best shielding
gas for your application​.
Figure 7.3​ - Shielding Gas Selector Chart
34

7.2. Effects of Shielding Gases
Carbon Dioxide performs very well over mill scale, rust, oil and other surface
contaminants. The higher the carbon dioxide content the higher the voltage should be to
maintain a stable arc. As carbon dioxide content increases, the penetration profile
becomes broader as can be seen below.
Figure 7.4​ - As carbon dioxide content increases the width of the weld nugget increases. The rounder the
penetration profile the better the welding procedure can compensate for changes to the electrode position
and the transverse angle used by the welder.
Carbon dioxide is a reactive gas, meaning that there will be chemical reactions in the arc
and molten weld pool. The main effect is that as carbon dioxide content in a shielding
gas mix increases tensile strength decreases and vice versa. Carbon dioxide is the
cheapest alternative for shielding. Regardless of being cheap, it still has significant
benefits. Carbon dioxide will provide a very round penetration profile as can be seen in
Figure 7.4 (C) ​above. If the base material is not perfectly clean, it will do a good job of
welding over moderate quantities of rust, mill scale and even paint. Please keep in mind
that regardless of what shielding gas is being used, a clean joint is always preferred in
order to assure quality.
Oxygen is also a reactive gas and provides a couple of significant benefits. It requires a
much lower amperage to allow for spray transfer in GMAW applications. This means
reduced heat input and better operator appeal. It also provides a very flat face by
improving puddle fluidity and arc stability. A downside of using oxygen is that it causes
oxidation of the weld metal. Because of this reason, it is not recommended for use in
welding aluminum, magnesium, copper and other exotic metals. It can be used in
stainless steel welding but should never exceed 3% of the shielding gas.
Argon is an inert gas which means it does not facilitate chemical reactions as carbon
dioxide and oxygen do. Argon is typically used in the range of 75 to 95% of the shielding
gas mix when welding carbon steel and up to 98% when welding stainless steel.
Aluminum welding is done with 100% argon and in some cases it can be an
35

argon-helium mix. Argon allows for spray transfer in GMAW when it reaches or exceeds
78% of the shielding gas mixture. Argon provides arc stability, puddle control and
reduces spatter as the content goes up. As argon content goes up the penetration
profile becomes narrower as can be seen in Figure 7.4 (A-B).
Helium ​is another inert gas. It is not typically used in carbon steel application but can be
added to helium for use primarily in aluminum and other non-ferrous applications. It can
also be used for GMAW welding of stainless steel in combination with argon and carbon
dioxide. Helium creates a higher energy arc than pure argon which allows for faster
travel speeds and higher productivity. Helium is many times more expensive than argon
and should only be used when absolutely necessary. You will also need to run a higher
flow rate which adds to the cost.
7.3. Submerged Arc Fluxes
In the submerged arc welding (SAW) process, shielding is provided by using flux. The
flux is a combination of carbonate and silicate materials which provide shielding from the
atmosphere. Fluxes also add alloying elements to the weld in order to affect mechanical
properties.
Regardless of the type of flux and quantities of alloying elements, all fluxes provide
shielding from the atmosphere in the same way. They blanket the molten puddle while it
is molten. Part of the flux becomes weld metal and some will form slag - similar to
FCAW and SMAW. Some flux will remain unused. This flux may be recycled and used
for further welding. Any time you are recycling flux it is recommended that you add virgin
(unused) flux at a 1:1 ratio.
36

Figure 7.5 ​- The submerged arc welding process utilizes gravity to feed the flux which provides shielding
from the atmosphere as well as adding alloying elements to attain specific mechanical properties.
Fluxes are categorized by how they are manufactured: agglomerated, fused, bonded
and mechanically mixed fluxes. The other way to categorize them, and perhaps the
most important way, is by how they affect the deposited weld metal: active, neutral and
alloy fluxes.
Active fluxes are defined by the American Welding Society as those which contain
small amounts of manganese and silicon. These deoxidizers improve performance by
providing better resistance to porosity and weld cracking caused by contaminants in the
base metal.
Active fluxes are primarily used for single pass welds. The alloy in the weld deposit of
active fluxes will vary with changes in the arc voltage. The higher the alloy content the
higher the strength. This may or may not be desired. It all depends on the intended
service of the welded component. It is important that a WPS tightly controls voltage
when using active fluxes, especially in multiple pass applications.
Active fluxes are not recommended for welding material over 1 inch [25 mm] thick.
Neutral fluxes do not produce a significant change in weld metal composition even with
significant changes in arc voltage. They perform well in multiple pass applications and
are recommended over active fluxes when welding sections over 1 inch [25 mm].
37

The downside of using neutral fluxes is that they are more prone to weld discontinuities
such as porosity and cracking, especially in single pass welds.
Alloy fluxes are those used in carbon steel to make an alloy weld deposit. Their primary
use is in hardfacing applications. They are also active fluxes so the arc voltage must be
carefully controlled as it can have a significant impact on important mechanical
properties like strength and hardness.
7.4. Selecting the Right Wire/Flux Combination
Similar to how we select filler metal for other processes, we must start by determining if
we need matching strength or if we can undermatch. The strength of a SAW weld is a
product of both the wire and flux and thus we need to consider them together. Below is
how wire/flux combinations are classified by the American Welding Society.
Figure 7.6 ​- AWS Classification of wire and flux combinations
There will be many wire/flux combinations that provide the strength needed. And just
like with other processes, you need to know if a weld will be subjected to post weld heat
treatment. Remember, doing PWHT reduces strength. So if you need 70ksi tensile
strength after PWHT make sure the “P” is part of the AWS classification.
38

Fluxes are designed with specific benefits in mind. There are fluxes that are good for
very fast travel speeds. There are others that solidify quickly and makes them extremely
useful in small diameter pipe SAW welding. Other fluxes provide resistance to porosity.
Others have improved slag detachability for narrow groove applications. Some fluxes
are well rounded and will have many of these characteristics.
You cannot tell all this from the AWS classification. You must go to the manufacturer’s
literature to find this information. See the example below.
Figure 7.7 ​- Literature from Lincoln Electric describing the advantages of different fluxes. It is vital to pick the
one that best suits the application.
Other manufacturers provide this same type of information. So, regardless of what brand
of electrode and flux you use, you should be able to find a flux that is specific to your
application.
39

8. WELDING POSITION
Welding position is very important as it can have a significant effect on quality and
productivity. In the vast majority of cases we want to weld in the horizontal and flat
positions. These positions allow us to have the highest deposition rates and require
lower welder skill. When we weld vertical or overhead we have to reduce our amperage
to prevent the puddle from dripping down due to gravity. This means much lower
deposition rates and lower productivity.
Because of the significant effect that welding position has on productivity, many
fabricators choose to make an investment in manipulating equipment to be able to move
the parts so that welding is always done in the flat or horizontal positions. Smaller parts
which are easier to manipulate should always be welded in these positions as well.
If the part cannot be manipulated and welding cannot be done in position (flat or
horizontal) we must take this into consideration when developing our welding
procedures, choosing the right welding process and selecting the right filler metal. This
was explained in Section 2 - Welding Processes (Joint Type and Welding Position).
One important decision that often needs to be made is whether to make vertical welds
with an uphill or downhill progression.
Downhill (vertical down) welds provide extremely fast travel speeds but are highly
susceptible to lack of fusion and undersized weld throats. Welds made using the FCAW
process with downhill progression are also susceptible to slag inclusions. Because of
extremely fast travel speeds, vertical down welds can have very high cooling rates which
may lead to hydrogen induced cracking in thick sections.
Figure 8.1 -​ Welds made in the 3F position with downhill progression. Both weld exhibit lack of fusion.
40

Uphill (vertical up) welds are very slow compared to welding downhill. However, they
can easily achieve root fusion aided by much higher heat inputs. The heat input is
higher due to the slow travel speed even though amperage and voltage may be much
lower than when welding downhill. Welding uphill may be challenging as it requires a
much higher level of skill. Processes that produce slag, such as FCAW and SMAW may
facilitate uphill welding. The slag produced by these processes helps by holding up the
puddle.
Don’t assume that when welding in the flat and horizontal positions lack of fusion is not a
concern. Using inadequate welding procedures can still cause lack of fusion as well as
other discontinuities.
Figure 8.2 ​- FCAW weld made in the 2F (horizontal) position with 0.045” [1.2mm] E71T-1 FCAW electrode.
The weld shows lack of fusion and possible slag inclusion.
From the exterior, the weld above looked acceptable. Because of the size (5/16”), the
weld sagged a bit but still had an acceptable bead profile. This shows the importance of
running qualification tests to verify proper fusion. The weld above was made with a
prequalified welding procedure. This is proof that using prequalified welding procedures
is not a guarantee that you’ll produce sound welds.
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9. ELECTRICAL CHARACTERISTICS
Electrical characteristics include both the mode of metal transfer and the type of current.
The type of current will be dictated by the process you use. GMAW, MCAW and
FCAW-G will always be done with direct current electrode positive (DCEP), FCAW-S will
always be done with direct current electrode negative (DCEN). GTAW will either be
done with alternating current (AC) or direct current electrode negative (DCEN). Finally,
SMAW and SAW can be done in all three: AC, DCEP and DCEN depending on the
electrodes being used and penetration requirements.
Mode of metal transfer typically only applies to the GMAW process. The modes of metal
transfer are:
●
●
●
●
Short circuit
Globular
Spray
Pulse Spray
The mode of metal transfer is dictated by amperage, voltage and shielding gas. Each
mode of metal transfers has distinctive characteristics which makes them unique. They
all have advantages and limitations.
9.1. Short Circuit Transfer
Short circuit transfer, commonly called “short arc” and formally called GMAW-S, is a
mode of metal transfer with low heat input where the transfer of metal from the electrode
to weld puddle occurs by a series of electrical shorts. As the welding wire is fed it makes
physical contact with the base material and creates a short. As the short occurs the
voltage immediately drops to zero. However, GMAW welding machines are constant
voltage power sources and their main job is to keep the voltage constant. In order to do
so in the presence of a short, which wants to drive the voltage to zero, the power source
will increase the amperage to break the short.
The short is essentially blasted away by the spike in amperage causing an explosion of
sorts. This explosion generates spatter and the crackling noise associated with this
mode of metal transfer. Every time the wire shorts to the base metal the welding arc is
extinguished. The welding machine will react instantaneously with the spike in amperage
to eliminate the short and reignite the arc. This happens many times per second (up to
200 times per second!) which is why we never see the arc go out.
42

Figure 9.1 - This plot of amperage and voltage in relation to time shows how the short brings the voltage to
zero and at the same time the power sources increases amperage to break the short​.
Short circuit transfer generates low heat input due to the low amperage and low voltage
used. Because of this, it is limited to thin materials. The American Welding Society
prohibits the use of short circuit transfer in prequalified welding procedures because of
the high probability of lack of fusion.
Typical shielding gases for short circuit transfer include 100% carbon dioxide and mixes
containing up to 75% argon with the balance being carbon dioxide.
Advantages of Short Circuit Transfer
●
●
●
●
Good for thinner materials (1/8” and under) – low heat input prevents blowing
through the base material and as long as the travel speed is adequate can also
prevent distortion.
All-position welding - due to the low heat input the puddle solidifies quickly which
allows for welding in all positions.
Great for gaps and bad fit up – short circuit transfer is good for bad fit-up,
including gaps. Short circuit transfer is widely used to run the root pass on pipe
because of this same reason.
Low cost – The low amperage requirement of short circuit transfer means that
basic, low-end power sources can be used. Carbon dioxide is also relatively
inexpensive compared to other shielding gas mixes with high argon content.
Limitation of Short Circuit Transfer
●
●
Limited to sheet metal – as mentioned above, the low heat input produces lack of
fusion on thicker sections.
Spatter – the shorting of the arc and subsequent blasting of the arc by the spike
in amperage generates spatter which increases clean up time and reduces the
electrode efficiency.
43

●
Not allowed for use in prequalified welding procedures (due to susceptibility to
lack of fusion).
9.2. Globular Transfer
Globular transfer occurs in the GMAW and MCAW processes after we exceed a certain
current for a specific wire diameter. Instead of having the metal transfer via a series of
shorts as in short circuit transfer, in globular transfer gravity pulls down on large metal
droplets (globs) that form at the end of the electrode due to the high currents associated
with this mode.
Figure 9.2 ​- Globular transfer produces large and irregular droples (globs) which are pulled down towards
the weld puddle by gravity.
These large and irregularly shaped droplets don’t always fall straight down. Rather,
some droplets can be expelled beyond the weld puddle resulting in large amounts of
spatter. Because of the large size and high energy carried by the droplets, spatter from
globular transfer can fuse to the base metal making it harder to remove.
The difference between globular and short circuit transfer is in the current and voltage
levels. Globular uses higher currents and higher voltages. For GMAW wires the current
at which short circuit stops and globular transfer starts are listed below:
● .023" 90 amps
● .030" 145 amps
● .035" 180 amps
● .045" 250 amps
44

These numbers are approximates and there is no clear cut transition point. Instead,
there will be a combination of short circuit and globular transfer for a range of amperage
before the transfer becomes exclusively globular.
The shielding gas for globular transfer is typically 100% carbon dioxide and
argon/carbon dioxide mixes with up to 75% argon content. If the argon content rises to
about 78% or more, we would transition from globular into spray.
Advantages of Globular Transfer
●
●
●
Low cost – basic constant voltage equipment and relatively inexpensive carbon
dioxide shielding gas may be used.
High heat input permits the welding of thick sections
Lower emitted heat compared to spray (for operator comfort)
Limitations of Globular Transfer
●
●
●
●
Excessive spatter increases rework (time spent removing spatter)
Excessive spatter decreases the efficiency of the electrode (wasted filler metal)
Limited to the flat and horizontal positions due to large fluid weld puddle
Erratic/Inconsistent arc
9.3. Spray Transfer
Spray transfer is a mode of metal transfer in which a fine spray of metal droplets are
projected axially from the tip of the electrode to the work. These droplets are smaller in
diameter than the electrode. This mode of metal transfer is characterized by high wire
feed speeds (high amperage), high voltage and high heat input. It produces a very fluid
weld puddle so it can only be used in the flat and horizontal positions.
Figure 9.3 - In spray transfer fine droplets are transferred through the arc. This produces deep
penetrating and typically spatter free welds.
45

The welds produced with spray transfer are characterized by deep penetration and
excellent bead appearance, provided proper welding technique is used.
In order to achieve spray transfer, the welding procedure should be such that it provides
amperage above the transition current for the diameter of electrode being used and the
corresponding voltage to achieve a stable arc. The amperage level at which we attain
spray transfer is dependent primarily on two variables:
●
●
Shielding gas composition
Electrode diameter
As explained previously, the mode of metal transfer is directly influenced by amperage,
voltage and shielding gas composition. In order to achieve spray transfer the shielding
gas should contain at least 78% argon (inactive/inert gas) with the balance being most
commonly carbon dioxide and in some cases oxygen (at levels of 5% or lower). Gases
of these compositions provide a stable medium for the metal droplets to transfer
smoothly through the arc.
Because different gas mixtures have different energy levels and other specific
characteristics, spray transfer is achieved at different current levels for a specific
electrode diameter depending on the shielding gas composition.
The table below provides.
Figure 9.4 ​- approximate transition currents to achieve spray transfer based on electrode diameter
and shielding gas composition.
The chart above provides the estimated current at which spray transfer can be achieved.
There are other factors that will affect the arc such as voltage. If your voltage is too low
your arc will be erratic and you won’t have a good transfer. You also need to pay
attention to other factors that affect amperage, such as your contact-tip-to-work distance
(CTTWD). This is the main reason why the chart shows amperage rather than wire feed
speed. For a given wire feed speed, the resulting amperage will decrease as your
46

CTTWD increases and vice versa.
section 13.
The effects of CTTWD are further explained in
It is important to note that as the percent of argon increases in the shielding gas, the
transition current drops for a given electrode diameter. Spray transfer can be achieved
at a much lower current when using 95/5 (argon/oxygen) than with 90/10 (argon/carbon
dioxide).
Advantages of Spray Transfer
●
●
●
●
●
High heat input which can provide deep penetration
Higher wire feed speeds (amperage) produce high deposition rates which
increase productivity
Very clean, spatter free welds possible
Good choice for thicker sections (1/4-inch and thicker)
Allows for use of prequalified welding procedures
Limitations of Spray Transfer
●
●
●
●
●
Use is limited to the flat and horizontal positions due to puddle fluidity
Potential for burn-through on thinner materials
Potential for undercut due to high voltage levels
More expensive gas than for short circuit or globular
Higher levels of radiated heat – uncomfortable for the welder
9.4. Pulsed Spray Transfer
Pulsed spray refers to a GMAW mode of transfer in which metal droplets are transferred
through the arc with changes in amperage produced by the power source. The power
source provides a pulsing peak current that raises the amperage above the transition
current and allows for axial spray transfer. This peak current is only applied for a short
time (measured in milliseconds) and then a background current takes over. The
background current is high enough to keep the arc lit, but low enough to prevent metal
transfer, meaning metal transfer only occurs while the peak current is applied.
Ideally, only one droplet is transferred per pulse. Most pulsing machines will cycle
between peak and background currents at a rate of 100 to 400 times per second.
Higher end power sources will allow the user to vary this frequency along with the
amount of time that is spent on peak and background currents. These advanced options
are useful in critical applications where heat input is critical.
In order to achieve pulsed spray metal transfer, we need to meet all the requirements of
spray transfer which are:
47

●
●
Shielding gas argon content of at least 78% (balance carbon dioxide or oxygen
up to 5%)
Welding current above transition point for the wire diameter being used (only
peak current has to be above)
Pulse spray has many benefits, but unfortunately many see it as a cure for all welding
problems. Unfortunately this just isn’t the case. It is important to understand how pulse
can do things like reducing spatter, reducing distortion and improving deposition rates. It
works in certain applications, but not all. Blindly assuming it will do all three of these
things every time is asking for trouble.
Advantages of Pulse Welding
●
●
●
●
●
Reduction in spatter – this reduction is associated with pulse being done in spray
transfer, thus eliminating spatter. Spatter can still occur if the base metal is dirty
or contaminated with oil, grease, rust, paint or other contaminants.
Higher deposition rates for out-of-position welding – this is due to the rapid
cooling of the puddle during the background part of the cycle. This allows the
puddle to cool quicker so larger puddles (higher wire feeds speeds and thus
higher deposition rates) can be carried in the vertical up and overhead positions.
Reduction in overall heat input - useful in thinner materials and to reduce
distortion
Good on thin materials – at a given wire feed speed pulse will have a lower
average amperage than the other modes of transfer. This makes it very useful
when welding sheet metal.
Reduces fume levels – pulsed spray transfer can reduce fume generation
compared to all three other modes of transfer.
Limitations of Pulsed Spray Transfer
●
●
●
Cost of equipment – the equipment necessary for pulsed spray transfer requires
more hardware and is more expensive than conventional step-down transformer
power sources.
Cost of gas – the gas blends required for pulse welding are more expensive than
the commonly used 100% CO2 or 75%Argon/25% CO2 gas for short circuit​ ​and
globular transfer modes.
Higher radiated heat – high arc energy produces higher levels of radiated heat
and a brighter arc compared to short circuit and globular transfer. This means
welding can become uncomfortable for the welder. However, pulsed spray should
produce much less radiated heat than spray.
48

10. TECHNIQUE
Technique refers to some of the variables that are controlled by the welder: running
stringers or weaves, single or multiple pass welds, contact tip to work distance and other
operations done before welding, in between welding passes and after welding.
10.1. Stringer versus Weave
Stringer technique is where the welder does not do any form of puddle manipulation.
The welding motion is constant and always points the electrode right at the root of the
joint. It provides deeper and more consistent penetration than a weave.
Weaving allows for wider welds and facilitates welding in the vertical position when using
an uphill progression. Weaving is susceptible to lack of root fusion if improper technique
is employed. The image below shows what taking weaving to the extreme (very large
oscillations) can cause.
Figure 10.1 - From the exterior both welds look acceptable. Both welds were made with .035”
ER70S-6 wire and 90% argon / 10% carbon dioxide gas. Weld (A) was made at 350 in/min using a
weave technique while weld (B) was made at 550 in/min using a stringer technique (no
manipulation).
From the exterior both welds have acceptable appearance. They achieved the required
weld size, but the weaving technique failed to achieve root fusion. Weld (B) had higher
amperage, but the procedure for weld (A) should have yielded better results. Part of
49

this may have been due to welder skill; however, a stringer will always provide deeper
and more consistent penetration when both techniques are used properly.
10.2. Single versus Multipass
The decision to make a weld in one or multiple passes is typically driven by the
necessary size of the weld. However, there are instances where a specific size may be
achieved in a single pass or in multiple passes. This is common in groove welds which
can handle relatively large weld passes.
If you look at the requirement for prequalified welding procedures in AWS D1.1 you’ll
notice that there are limits to maximum single pass fillet weld sizes and also weld pass
thickness in groove welds. These limits exist because making a weld too big can have
detrimental effects on the quality of the weld.
One of the biggest problems with single pass welds that are too big, is susceptibility to
lack of fusion and slag inclusions. This is due to the puddle running ahead of the arc. In
this case the electrode is being driven into the weld puddle rather than directly at the
joint. This causes lack of fusion. In processes with slag such as FCAW, SMAW and
SAW, it creates slag inclusions.
Bigger single pass welds will also have much higher heat inputs than their smaller size
counterparts. This may be good or bad depending on the application. High heat input is
good when we are welding thick sections or steels with a microstructure susceptible to
cold cracking. The higher the heat input the slower the cooling rate. The slower the
cooling rate the more time available for hydrogen to diffuse out of the weld and less of a
chance for martensite (brittle microstructure) to form, thus decreasing susceptibility to
cracking.
Another benefit of larger passes is less distortion for the same size weld. For example, a
⅜” fillet weld made in one pass will produce less distortion than a ⅜” fillet weld made in 3
passes. This is due to the reduction in the number of heating and cooling cycles.
Smaller passes come with higher travel speeds if the welding parameters remain the
same. Higher travel speeds reduce heat input. This means faster cooling rates. This is
not typically a problem unless our welds get too small. If you take a look at AWS D1.1
you’ll notice that there are minimum weld sizes specified for different base metal
thicknesses. This is due to the fact that if a weld is too small and has a very low heat
input, the cooling rate may be too high and the weld and heat affected zone may
become brittle due to the formation of martensite.
50

The size of a single weld pass can also have an effect on weld toughness, or its ability to
resist the propagation of a crack. By having more welding passes, as opposed to a
single large pass, additional grain refinement occurs. This in turn increases toughness
values.
10.3. Contact Tip to Work Distance (CTTWD)
If you look at any of the structural welding codes you’ll notice that
contact-tip-to-work-distance (CTTWD) is a variable which must be listed in welding
procedure specifications. However, it is not an essential variable, meaning that changes
to CTTWD of any amount do not require requalification. This can seem puzzling to
some, especially those that understand how critical CTTWD is due to its effects on
amperage.
CTTWD is extremely important because even slight changes can cause significant
changes to our welding current. At a given wire feed speed we can have a swing of over
50 amps if we go from a ½-inch CTTWD to 1-¼-inch in the GMAW, MCAW and FCAW
processes.
The reason why CTTWD is not an essential variable is because although it affects
amperage, amperage itself is an essential variable. This creates a problem. A perfectly
written WPS may call for a ¾” CTTWD. If the welder runs a 1-½” CTTWD the amperage
may drop below what is allowed by the WPS. If there is no one monitoring current at the
time, no one would know that a weld or welds were made in violation of the WPS.
To illustrate the importance of CTTWD take a look at Figure 10.2.
All three of these welds were made with the exact same parameters with the exception
of the CTTWD. The procedure was .045” ER70S-6 at 375ipm 27.5V with 90Ar/10CO2
shielding gas. The desired weld size was ¼”. Below are the values for CTTWD and the
resulting amperage.
A. ⅜” CTTWD → 354 amps
B. ¾” CTTWD → 278 amps
C. 1-½” CTTWD → 219 amps
51

Figure 10.2 - Welds done with the same welding parameter with the exception of CTTWD. The values for
CTTWD were (A) 3/8”, (B) 3/4” (C) 1-½”.
Welding procedure (A) provides very deep penetration, so when the CTTWD is
increased and amperage drops significantly in procedure (B) we still achieve fusion to
the root and even get a good amount of penetration into the root. By further increasing
the CTTWD our amperage drops even further, but we still achieve root fusion as seen in
image (C).
WARNING: This success with completely different CTTWDs is a testament to a properly
developed WPS. However, if the WPS barely passed the qualification tests, meaning
fusion to the root and side walls was achieved, but there was very little if any
penetration, then slight increases to CTTWD may create lack of fusion.
The problem lies when our welding procedure is not this robust. Imagine we are using
0.035” wire and running at 140 amps. What happens if we increase our CTTWD too
much and our amperage drops to 90 amps? Would we still get fusion to the root and
sidewalls? What if on top of this change we also have mill scale? You are almost
guaranteed lack of fusion.
In the example in Figure 10.2, our PQR was run at the 278 amps. Following AWS D1.1
we would have an acceptable range for amperage in our WPS of +/- 10% or 250 - 306
amps. As you can see, the changes to CTTWD create an issue where we are outside of
the allowable range for amperage and thus in violation of the WPS. An inspector may
have an issue with welds made when the amperage is 219 as in (C) above, even though
it produces acceptable results. The inspector will only know that the weld is outside the
52

allowable range and mark the weld as suspect even though visual inspection of the weld
was acceptable.
Skilled welders are able to maintain an adequate CTTWD. And when this CTTWD gets
too large there are changes to the arc characteristics that the welder can see and
immediately correct. However, sometimes this excessive CTTWD is not due to welder
skill, or lack thereof, but due to reach issues. There are many reasons why our CTTWD
can change dramatically. It is important to understand the implications of this. If it
happens too often it may be time to reevaluate how welding is being done.
10.4. Peening
Peening is sometimes specified when welding highly restrained joints which produce
high levels of residual stress. Peening introduces compressive stresses into the weld
which alleviate the tensile residual stresses that result when welding highly restrained
joints.
10.5. Interpass Cleaning
When multiple passes are required to achieve the required weld size, the welding
procedure may specify the type of interpass cleaning. This is specially important in
processes that produce slag such as FCAW, SMAW and SAW.
The goal is to remove all slag and silica islands before the next pass. This may be done
with a simple wire brush, a wire wheel, a grinder or many other ways. There are times
where a specific tool is called out to prevent problems associated with other methods.
Backgouging is listed in the Joint Design section of the WPS, but it is a form of interpass
cleaning. Backgouging does not only clean the joint, but will also open up the joint in
order to achieve complete joint penetration when welding from both sides.
53

11. PREHEAT AND INTERPASS TEMPERATURE
Preheating of structural steels is carried out primarily to slow the cooling rate after
welding to prevent the formation of martensite. Martensite makes the weld and the heat
affected zone (HAZ) very hard and brittle. This newly formed microstructure is
susceptible to cracking, especially in highly restrained joints and in the presence of
hydrogen. By slowing the cooling rate we reduce or eliminate the formation of
martensite and thus reduce cracking susceptibility.
The two questions that must be answered when developing a welding procedures in
regards to preheat are:
●
●
Is preheat necessary?
If preheat is necessary, what should be the minimum and/or maximum preheat
temperature?
Note that the interpass temperature will almost always be the same as the same as the
preheat temperature. In some cases a maximum interpass temperature will be
specified.
11.1. Determining if Preheat is Necessary
In carbon and low alloy steels preheat may become necessary when the carbon content
reaches a certain limit. It may also be necessary based on material thickness.
A simple way to determine if preheat is necessary is to consult the structural welding
code for steel, AWS D1.1. In the latest edition of the code you can look at ​Table 5.8 -
Prequalified Minimum Preheat and Interpass Temperatures​. This table will provide
preheat and interpass temperatures for different structural steels based on their chemical
composition, thickness and whether a low hydrogen welding process is being used.
If you can’t find the steel you're working with in this list you should consult the
manufacturer of the steel to see if preheat is necessary.
Below is a list of instances when you must consider the use of preheat:
●
●
●
●
Carbon content is 0.30% of higher
Thickness of base metal being welded is ¾” or thicker
Welding on high strength steels
Welding on quenched and tempered steels
54

Once you determine that preheat is necessary you must then determine the right amount
of preheat (temperature). There are many ways to calculate this value.
11.2. Determining Preheat and Interpass Temperature
There are different ways to determine what the preheat temperature needs to be. The
benefit of some of these methods is that you can determine the preheat temperature not
based on a standard that provides extremely conservative values, but rather based on
the material’s chemistry which will provide a more accurate result. By doing this you
may determine that the preheat temperature is much lower than that published in tables
such as Table 5.8 of AWS D1.1 which, as mentioned above, states the minimum preheat
and interpass temperatures for structural steels. This can end up saving you a lot of
money by reducing the preheating time and reducing fuel consumption.
Figure 11.1 - Preheating is used primarily to reduce the cooling rate of the weld, heat affected zone and
adjacent base metal. This reduces susceptibility to cold (hydrogen induced) cracking.
The necessary preheat temperature depends on 3 things:
●
●
●
Whether or not a low-hydrogen process is used
The thickness of the steel
The chemistry of the steel
Some steels should not be welded with anything other than low-hydrogen electrodes.
Be sure to use the right electrode for the steel you are welding. Assuming you are using
55

the right electrode the table below provides safe preheat and interpass temperature for
structural steels. Structural steels as defined by AWS D1.1 Structural Welding Code as
“carbon or low alloy steels that are 1/8 in [3 mm] or thicker with a minimum specified
yield strength of 100 ksi [690 MPa] or less.”
The wording above may be a bit confusing. So to clarify, any carbon steel that has a
specified minimum yield strength above 100ksi should not follow the recommendations
on AWS D1.1, rather, it should consider other ways to determine preheat and interpass
temperatures.
11.3. Preheat and Interpass Temperature for Structural Steels
The following preheat and interpass temperatures are in line with those recommended in
AWS D1.1 Structural Welding Code - Steel for use in prequalified WPSs. The steels in
this list all fall within the scope of AWS D1.1, meaning they have a maximum specified
minimum tensile strength of 100 ksi.
Preheat and interpass temperature values are lower when using a low hydrogen process
since the purpose of preheating is to reduce hydrogen induced cracking. If you’d like to
have a quick, go-to reference you can use the table below. These preheat values allow
you to use non-low hydrogen processes such as SMAW with E6010, E6011, E6013,
E7024 and other non-low hydrogen electrodes.
Figure 11.2 ​- Conservative preheat temperatures for structural steels
As you’ll see from tables later in this section, using a low hydrogen process allows for
lower preheat and interpass temperatures. But if you need a quick reference the above
table provides values that will work for structural steels. Remember that Q&T steels may
have stricter requirements which need to be evaluated before making a decision on
preheat.
More specific preheat values for structural steels
56

CATEGORY A
For the following steels, follow the preheat and interpass temperature specified in Figure
11.3 when using SMAW with non-low hydrogen electrodes.
● ASTM A36
● ASTM A53 - Grade B
● ASTM A106 - Grade B
● ASTM A131 - Grades A, B, D, E
● ASTM A139 - Grade B
● ASTM A381 - Grade Y35
● ASTM A500 - Grades A, B, C
● ASTM A501 - Grade A
● ASTM A516 - Grades 55, 60
● ASTM A524 - Grades I, II
● ASTM A573 - Grades 58, 65
● ASTM A709 - Grade 36
● ASTM A1011 SS - Grades 30, 33, 36 (Type 1), 40, 45 (Type 1)
● ASTM A1018 SS - Grades 30, 33, 36, 40
● API 5L - Grades B, X42
● ABS - Grades A, B, D, E
Figure 11.3 - Minimum preheat and interpass temperature for Category A structural steels using non-low
hydrogen processes
There are certain steels and grades/types of steels that do not appear in the list above.
If they are not listed, then the use of low hydrogen electrodes may be necessary.
CATEGORY B
57

For the following steels use the preheat and interpass temperatures shown in Figure
11.4.
● ASTM A36
● ASTM A53 - Grade B
● ASTM A106 - Grade B
● ASTM A131 - Grades A, B, D, E, AH 32, AH 36, DH 32, DH 36, EH 32, EH 36
● ASTM A139 - Grade B
● ASTM A381 - Grade Y35
● ASTM A500 - Grades A, B, C
● ASTM A501 - Grade A, B
● ASTM A516 - Grades 55, 60, 65, 70
● ASTM A524 - Grades I, II
● ASTM A572 - Grades 42, 50, 55
● ASTM A573 - Grades 58, 65
● ASTM A588
● ASTM A595 - Grades A, B, C
● ASTM A606
● ASTM A618 - Grades Ib, II, III
● ASTM A633 - Grades A, C, D
● ASTM A709 - Grade 36, 50, 50S, 50W, HPS50W
● ASTM A710 - Grade A, Class 2 > 2in [50 mm]
● ASTM A847
● ASTM A913 - Grade 50
● ASTM A992
● ASTM A1008 HSLAS - Grade 45 Class 1 & 2, Grade 50 Class 1 & 2, Grade 55
Class 1 &2
● ASTM A1008HSLAS-F - Grade 50
● ASTM A1011 SS - Grades 50, 55
● ASTM A1011 HSLAS - Grade 45 Class 1 & 2, Grade 50 Class 1 & 2, Grade 55
Class 1 & 2
● ASTM 1018 HSLAS-F - Grade 50
● ASTM A1018 SS - Grades 30, 33, 36, 40
● ASTM A1066 - Grade 50
● ASTM A1085
● API 5L - Grades B, X42
● API Spec. 2H - Grades 42, 50
● API 2MT1 - Grade 50
● API 2W - Grades 42, 50, 50T
● API 2Y - Grades 42, 50, 50T
● ABS - Grades A, B, D, E, AH 32, AH 36, DH 32, DH 36, EH 32, EH 36
58

Figure 11.4 - Minimum preheat and interpass temperature for Category B structural steels using
low-hydrogen processes
CATEGORY C
For the following steels, use the preheat and interpass temperatures shown in Figure
11.5.
● ASTM A572 - Grades 60, 65
● ASTM A633 - Grade E
● ASTM A709 - Grade HPS70W
● ASTM A710 - Grade A, Class 2 ​<​ 2in [50 mm]
● ASTM A710 - Grade A, Class 3 > 2in [50 mm]
● ASTM A913 - Grades 60, 65, 70
● ASTM A1018 HSLAS - Grade 60 Class 2, Grade 70 Class 2
● ASTM A1018 HSLAS-F - Grade 60 Class 2, Grade 70 Class 2
● ASTM A1066 - Grades 60, 65, 70
● API 2W - Grade 60
● API 2Y - Grade 60
● API 5L - Grade X52
Figure 11.5 - Minimum preheat and interpass temperature for Category C structural steels using
low-hydrogen processes
59

CATEGORY D
For the following steels, use the preheat and interpass temperatures shown in Figure
11.6.
● ASTM A710 - Grade A (All Classes)
● ASTM A913 - Grades 50, 60, 65
Figure 11.6 - Minimum preheat and interpass temperature for Category D structural steels using
low-hydrogen processes capable of depositing weld metal with a maximum diffusible hydrogen content of
8ml/100g of weld.
CATEGORY E
● ASTM A1066 - Grades 50, 60, 65
Figure 11.7 - Minimum preheat and interpass temperature for Category E structural steels using
low-hydrogen processes
There are a few very important points when it comes to preheat. These points receive
special attention in AWS D1.1 and you must consider them when developing WPSs for
carbon steels, even if doing work governed by another code or no code at all.
●
When the base metal temperature is below 32°F [0°C], the base metal shall be
preheated to a minimum of 70°F [20°C] and the minimum interpass temperature shall be
maintained during welding.
60

●
●
●
●
●
For ASTM A709 Grade HPS 70W and ASTM A852, the maximum preheat and interpass
temperatures shall not exceed 400°F [200°C] for thicknesses up to 1-1/2 in [40 mm],
inclusive, and 450°F [230°C] for greater thicknesses.
The use of high heat input welding processes such as submerged arc welding (SAW)
may allow for lower preheat temperatures
Preheat temperature readings must be taken at a distance equal to the thickness of the
thicker member being welded, but no less than 3 inches away from the joint just prior to
initiating the arc for each pass.
The preheat temperature should be at the specified value not just at the point where the
weld starts but through the entire length of the joint.
Minimum interpass temperatures should be the same as the preheat temperature unless
otherwise specified in the welding procedure specification (WPS).
11.4. Taking Preheat and Interpass Temperature Readings
Some welding procedures that properly specify preheat and interpass temperatures end
up with problems such as excessive hardness or cracking. This is because preheat is
not applied properly. In order to ensure preheat is applied properly it needs to be
measured in the right location. This is 3 inches [75 mm] away from the joint to be welded
for the entire length of the joint for parts that are 3 in [75 mm] or less in thickness. For
parts exceeding 3 in [75 mm] the measurement must be taken at a distance equal to the
thickness of the thickest part being joined.
For example, if a part is 4 in [100mm] thick then the preheat must be taken at a distance
of 4 in [100 mm] from the joint. The preheat temperature must be reached along the
entire length of the joint.
Figure 11.8 - Preheat temperature readings must be taken along the length of the joint at a distance equal
to the thickness of the thickets member away from the joint.
Please note that if you are welding dissimilar thicknesses you must use the thicker
member as reference. So welding 2 in to 5 in [50mm to 125mm] the preheat temperature
must be measured at a distance of 5in [125 mm] from the joint.
61

In similar fashion, if you are welding two types of steel which call for different preheat
and interpass temperatures, the temperature to be used would be the highest of the two.
12. POST WELD HEAT TREATMENT
Post weld heat treatment (PWHT) may be necessary for different reasons.
PWHT is done to maintain or improve material strength and mechanical properties and
to relieve residual stresses. In steel fabrication, the most common PWHT procedures
applied are post heating and stress relieving.
When we weld, we introduce enough heat to melt the base material. This elevated
temperature causes microstructural changes to the base material which can change very
important material properties such as tensile strength, hardness, ductility and toughness.
The degree to which these properties are affected depends on the chemical composition
of the base material and the cooling rate after welding. PWHT treatment requirements
are typically dictated by codes and standards and by any special requirements due to
the service conditions of the welded structure.
For steel fabrication the use of PWHT is driven by the need to resist brittle fracture via
post heating and to reduce residual stresses via stress relieving.
12.1. Postheating
Post heating is primarily done to avoid hydrogen induced cracking (HIC), also known as
cold cracking and hydrogen assisted cracking (HAC). In order for HIC to occur three
things must be present:
1. A susceptible base material microstructure (usually due to high levels of
carbon)
2. Threshold level of hydrogen
3. Elevated stress levels (internal or external)
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If you eliminate one of the three scenarios above, hydrogen induced cracking will not
take place. Post heating allows hydrogen to diffuse out of the weld and heat affected
zone (HAZ), thus reducing diffusible hydrogen below the threshold level.
The weld should not be allowed to cool to room temperature before post heating. HIC
will occur once the material temperature drops below 200F. Before this happens the
part must be heated to a specific temperature and held for a specific amount of time
which depends on the material type and thickness. This allows hydrogen to diffuse out
of the weld and prevent cold cracking upon reaching room temperature.
Codes and standards will specify temperatures and holding times. In general, you must
heat the part high enough to allow hydrogen to diffuse out of the weld and HAZ but not
high enough to create any type of microstructural change. Typically, this “bake out”
procedure is done between 300˚F – 600˚F [149˚C – 316˚C]. This temperature is held for
at least 1 hour per inch [25mm] of material thickness. Always consult the code you are
working with or the engineer in charge before developing your own post heating
procedure.
Charts showing post heating and PWHT temperatures and holding times should be
included with all WPSs. An example of this type of chart is shown below.
Figure 12.1​ - Sample PWHT chart for P91 steel. Actual temperature and holding times are determined by
material composition and thickness.
12.2. Stress Relieving
Stress relieving is the other common reason for applying PWHT. Stress relieving is
done at a much higher temperature and usually for a longer period of time than post
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heating. Stresses can develop in weldments due to high levels of restraint and
shrinkage forces. These stresses may not cause the part to crack right away, but
significantly reduce the fatigue life of the welded structure or component.
Stress relieving will reduce these residual stresses that are present after welding by
carefully controlling the heating of the part to a specific temperature, holding it for a
specific amount of time and then controlling the cooling rate. Unlike postheating, the
temperatures for stress relieving are much higher. For most carbon steels stress
relieving is done at 1000˚F – 1400˚F [538˚C – 760˚C].
Other than relieving stresses, PWHT provides other benefits: tempering, hydrogen
removal, improved ductility, toughness and corrosion resistance. However, be aware
that PWHT can also have damaging effects if done improperly or done on materials that
should not be post weld heat treated.
Exceeding the stress relieving temperatures can reduce tensile strength, reduce creep
strength and reduce notch toughness. Additionally, some steels should not be post weld
heat treated or at least it is not recommended. AWS D1.1 Structural Welding Code
(Steel) states that stress relieving the following common structural steels is not
recommended:
●
●
●
●
ASTM A514 (commonly referred to as T-1 steels – Arcelor Mittal trade
name)
ASTM A517
ASTM A709 Grade HPS 100W
ASTM A710
It is worth restating that any PWHT must be done according to the specific code or
standard that governs the fabrication of the structure or component. Even though PWHT
is done after welding it forms part of the welding procedure specification (WPS) and
clear instructions must be shown in this document on how to perform the PWHT.
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13. WELDING PROCEDURE (OPERATING PARAMETERS)
Finally, we are the point in which we will select the variables that we typically think of
when developing a WPS - amperage, voltage, travel speed, wire diameter and work and
transverse angles.
This section is extremely important since the values you select for these variables have
the biggest impact on quality and productivity. There are plenty of welding procedures
being used today that provide quality welds, conform to codes and pass all kinds of
audits. Because they are so reliable in terms of quality nobody tries to improve them, or
even conduct and evaluation to see if there is a better way. This can cost a fabricator
greatly.
13.1. Effect of Welding Variables on Productivity
A properly written welding procedure will provide the required quality by meeting the
acceptance criteria dictated by the governing code or other standard. It will also seek to
maximize productivity.
Consider the following two scenarios of WPS for GMAW when welding ⅜” carbon steel
in the 2F position.
WPS-1: ​.045” ER70S-6 at 245ipm wire feed speed and 25.5 volts using 90/10 gas.
WPS-2: ​.045 ER70S-6 at 385ipm wire feed speed and 27.5 volts using 90/10 gas
Both procedures will provide adequate quality as shown in Figure 13.1.
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Figure 13.1 ​- Weld (A) was produced at a wire feed speed of 375 in/min while weld (B) was produced at 450
in/min. Both welds were done with the GMAW process using 0.045” ER70S-6 at 27.5 volts with 90% argon /
10% carbon dioxide shielding gas. Both welds are approximately ¼” fillet welds.
Both welds attained significant penetration to root and into the sidewalls. Both welds
were of the desired size (¼” legs). Both welds use a welding procedure that does not
require a high level of skill or which can be adapted to relatively easily.
The difference in the welding procedures was wire feed speed (and an increase in travel
speed in weld (B) to remain with a ¼” fillet weld size. This difference in wire feed speed
of 75 in/min represents an increase in travel speed, and thus productivity of 20%.
This means that procedure (B) can produce 20% more linear feet of weld than procedure
(A) in the same amount of time. This increase in capacity over the course of a year can
be worth tens of thousands of dollars to a company.
Some fabricators will make this weld with even lower wire feed speeds in which case the
increase in productivity can be much greater.
13.2. Effect of Welding Variables on Quality
The selection of essential welding variables has a direct and significant effect on weld
quality. In this publication, weld quality means that a weld will meet the applicable
quality standard. The examples shown are compared to the acceptance criteria of AWS
D1.1 Structural Welding Code - Steel. Macros as shown in Figure 13.2 show the
penetration profile and bead shape. They also reveal discontinuities such as lack of
fusion, internal porosity, undercut, cracks and overlap.
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The outside appearance of a weld can provide some indication of quality, but it certainly
does not tell the whole story. Just because a weld looks good from the outside doesn’t
mean it is a good wel. See the images below.
Figure 13.2 - From the exterior both welds look acceptable. Both welds were made with .035”
ER70S-6 wire and 90% argon / 10% carbon dioxide gas. Weld (A) was made at 350 in/min using a
weave technique while weld (B) was made at 550 in/min using a stringer technique (no
manipulation).
As you can see from the images above, weld exterior appearance is not a good indicator
of weld quality. When we perform visual inspection all we can see is the exterior of a
weld. So how can visual inspection be an acceptable means of accepting or rejecting a
weld? Well, it can only be so if we know the welding procedure that was used. If a weld
passes visual inspection which means there are no surface discontinuities, meets profile
requirements and is of the right size, we can only truly accept that weld if we know that a
qualified welding procedure specification was used to make that weld. Otherwise, we
cannot be assured that the desired quality was achieved.
This shows how important the use of qualified welding procedures is. When a welding
procedure is developed it must be qualified by testing in accordance to the welding code
or standard that you are following. Only this way will you have assurance that a weld
that meets visual inspection criteria is in fact a good weld.
In the example above the difference in the welding procedures was the wire feed speed,
which has an effect on welding amperage and the welder technique (weave versus
stringer). Both of these variables are specified in a WPS.
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13.3. Testing of Welding Procedures
Any developed welding procedure must be qualified by testing. That is, we conduct a
series of nondestructive and destructive tests in order to verify that the WPS produces
welds that will meet the acceptance criteria.
Nondestructive tests typically include visual inspections, ultrasonic testing and
radiographic testing. Examples of destructive tests are macroetches (as those shown in
Figures 13.1 and 13.2), bend tests, fillet break tests and reduced section tensile tests.
Welding codes will dictate which tests are necessary to qualify a WPS. Whether you are
following an AWS structural welding code, ASME BPVC Section IX, API 1104 or any
other welding code or specification, these documents will indicate the required tests for
qualifying a welding procedure.
13.4. Using Prequalified Welding Procedures
Some welding codes permit the use of prequalified welding procedures. This means that
you can use a welding procedure as if it had been qualified, but without the need for any
kind of testing. However, there are strict requirements for the use of prequalified welding
procedures. It is not as easy as selecting a qualified joint and using the filler metal
manufacturer’s recommended operating parameters. There are limitations in terms of
material group, welding positions, bead thickness, maximum amperage, maximum
electrode size and joint configurations as well as other limits. The prequalification clause
of the codes that allow prequalified welding procedures will list all the requirements and
limitations.
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Figure 13.3​ - Sample Prequalified Welding Procedure Specification (WPS)
The reason for all the limitations and requirements is because when using a prequalified
welding procedure we are not doing any testing. The testing has been done by others and the
results have been verified. However, in order to have assurance of good results there are limits
imposed to make sure fabricators don’t deviate from what is known to work.
All these requirements are not as stringent as you may imagine, but it is crucial to understand
what they are. Once you have this figured out you can enjoy the advantages of using
prequalified welding procedures.
13.5. Selecting Welding Parameters
13.5.1. Amperage (Current)
Amperage, or welding current, is one of the most important variables in a welding
procedure specification. Regardless of the welding process, amperage has a
direct impact on penetration. The higher the amperage the deeper the
penetration. See Figure 13.4 below.
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Figure 13.4 ​- All three welds were made with the GMAW process using .045” ER70S-6 and
90Ar/10CO2 shielding gas. The only difference was the amperage.
As seen above, as the current (amperage) goes up penetration increases. In
GMAW and other wire processes amperage is increased by increasing wire feed
speed. When we increase wire feed speed, the deposition rate increases and
thus the travel speed must be proportionally increased to maintain the same weld
size.
In constant current processes such as SMAW and GTAW we set amperage on
the welding machine. In wire processes such as GMAW, FCAW-G, FCAW-S and
MCAW we set wire feed speed. Wire feed speed is directly correlated to
amperage. The higher the wire feed speed the higher the amperage.
Amperage may also have a significant effect on productivity. As amperage goes
up so does our deposition rate as stated above. So the more amperage the
more pounds per hour we deposit. As long as we maintain the same weld size,
our travel speed will increase, meaning we can weld more linear feet in the same
amount of time.
13.5.2. Voltage
Voltage, when set in the correct range, has little effect on penetration. Within this
range, the higher the voltage the lower the penetration. Higher voltage spreads
the arc out and deposits a wider bead. Less energy density is exhibited as the
voltage goes up, so penetration decreases. Keep in mind that if the voltage is
too low and you get an erratic arc you will start losing penetration.
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Figure 13.5 - ​These welds were all made with .045” ER70S-6 wire, 90% Argon/10% Carbon
Dioxide shielding gas at 375ipm wire feed speed. The only difference was the voltage.
As you can see, voltage has little effect on depth of penetration. However, it
significantly affects bead shape and penetration profile. When voltage is set low
you will start getting excessive reinforcement in the weld. Reinforcement doesn’t
add strength to the weld and may result in increased costs due to additional filler
metal required, as well as additional time to make the weld. If reinforcement gets
excessive the weld may fail the acceptance criteria of many codes, especially if
the weld will be subjected to fatigue loading.
When voltage is set too high the weld puddle becomes very fluid and the weld
may sag as can be seen in Figure 13.5 (C). When voltage is excessively high
you can also get undercut. When undercut exceeds a certain depth it becomes a
defect which must be repaired.
Figure 13.6​- Excessive voltage may cause undercut as seen in this weld. The arc energy melts the
base material but there is not enough filler metal to fill that void which then results in undercut.
Undercut is dangerous as it can significantly reduce the fatigue life of a welded connection.
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In constant current welding processes such as SMAW and GTAW the voltage
varies based on the welder’s arc length.
13.5.3. Travel Speed
Travel speed impacts more than just productivity. It is a variable which must be
stated in the WPS and must be followed. Most welders don’t really look at the
WPS for a travel speed. They are just used to the muscle movements required
to make a weld of the right size. And here is where some problems may occur.
Travel speed has an effect on many aspects of a weld. If all other variables are
held constant (i.e. amps, volts, wire feed speed, shielding gas, etc.) you can
expect what is shown in Figure 13.7 below.
Figure 13.7 ​- These welds were all made with the same welding parameters with the exception of
travel speed.
Travel speed will affect the following:
● Weld size - as travel speed increases weld size will decrease.
Conversely, as travel speed decreases weld size increases. This can be
seen on Figure 13.7 above.
● Heat input - as travel speed increases, heat input decreases as long as
the amperage and voltage don’t change and vice versa. Heat input is a
critical variable which is affected by amperage, voltage and travel speed.
● Penetration - within the acceptable range allowed by the WPS, increasing
travel speed will slightly decrease penetration. However,if the WPS was
properly qualified, the range of travel speed shown in the WPS should be
adequate to achieve root and side wall fusion within that entire set of
values. If travel speed gets excessively slow there is a chance that the
puddle may run ahead of the arc and penetration will decrease or even
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●
●
result in lack of fusion. Figure 13.7 shows how the slower travel speed
(C) yielded lack of root fusion.
Quality - naturally, if we have lack of fusion quality will be impacted.
Travel speeds which are too fast can also produce other weld
discontinuities such as undercut. Undercut may be caused by excessive
voltage, not enough wire feed speed or a travel speed that is too fast.
Productivity - the faster we weld the faster we get done, it is that simple.
However, keep in mind that if we have a specific weld size we must
achieve then in order to get that size of weld we must also increase our
deposition rate by increasing wire feed speed in wire processes or
amperage in constant current processes such as SMAW and GTAW.
13.5.4. Travel Angle
Travel angle refers to whether you push or pull (drag). There are certain
processes and applications where one is more advantageous than the other. In
processes that produce slag, it is advisable to have a pull/drag technique.
Pushing these types of processes may result in slag inclusions similar to the one
seen below.
Figure 13.8 - ​Slag inclusion preventing root fusion. This weld was made in the vertical (3F)
position with downward progression. It was made with a pull/drag angle which is advisable.
However, the puddle ran ahead of the arc and penetration was lost. This is similar to what happens
when we push a flux-cored wire and allow the puddle to run ahead of the arc.
GMAW and MCAW are not slag-producing processes so slag inclusions are not a
concern. In these welding processes pushing or pulling is acceptable as long as
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the angles are not excessively steep. A push or pull angle of about 10 - 15
degrees is acceptable.
There are subtle differences between pushing and pulling in GMAW and MCAW.
Pushing provides a flatter weld face while pulling produces a bit of a crown.
Pulling, however, achieves slightly deeper penetration than pushing. As just
mentioned, the differences are very slight and the technique should not be
chosen based on the amount of penetration required.
13.5.5. Transverse Angle
The transverse angle in a fillet weld or lap weld should be 45 degrees. There are
times when favoring one of the two members being joined may be beneficial, but
in general we always want to hit both sides equally even when welding different
thicknesses.
The image below shows welding of significantly different thicknesses. The
transverse angle was 45-degrees. A properly written WPS should not have the
need to favor the thicker section in order to get adequate penetration into both
members.
Figure 13.9 - Fillet weld joining ½” to ¼” ASTM A572 Gr 50 material. The transverse angle was 45
degrees.
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Figure 13.10 shows the effects of changing the transverse angle.
Figure 13.10​ - Effects of transverse angle. (A) has a steep angle favoring the bottom plate, (B) has
a transverse angle of 45 degrees, (C) has a transverse angle favoring the vertical plate.
13.5.6. Contact Tip to Work Distance (CTTWD)
Contact tip to work distance was explained in section 10.3 (Technique). Please
refer to that section for effects of CTTWD.
14. ADDITIONAL REQUIREMENTS
Additional requirements include limitations such as maximum single pass fillet weld size,
maximum root pass thickness, maximum layer width before splitting, etc. These are
notes that must be carefully followed to assure that the welding procedure produces
sound welds. When using prequalified WPSs these additional requirements will be
specified by the code.
You can add as much detail as you want in this section. A WPS is a set of instructions
for the welder to follow. The format/form used is not important as long as it
communicates all the right information to the welder. The more specific and the more
detail it has the better.
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Heat Input
In some applications heat input is going to be specified. It may be a minimum or a
maximum. The reason why heat input is critical in certain applications is because it
directly impacts the cooling rate. The higher the heat input the slower the cooling rate
and vice versa.
Typically, fast cooling rates are detrimental on carbon steel weldments because they
cause embrittlement in the weld and heat affected zone. In some steel welding
procedures a minimum heat input may be specified to ensure a cooling rate that is not
fast enough to deteriorate the mechanical properties of the weld and heat affected zone.
In other applications, such as when welding austenitic stainless steels (most 300 series),
a high heat input may be detrimental. Unlike carbon steel, stainless steel has very little
carbon so it does not harden as carbon steel does with fast cooling rates. Fast cooling
rates are actually desirable when welding austenitic stainless steels because it reduces
susceptibility to sensitization. Sensitization is a problem that leads to premature
corrosion in the heat affected zone of stainless weldments.
It is extremely important to understand how the base metal you are welding is affected
by heat input.
To calculate heat input you’ll need to measure your welding amperage, arc voltage and
travel speed. The formula for heat input is
Heat Input = (60 x Amps x Volts) / (1,000 x Travel Speed in in/min) = KJ/in
The 60 and the 1,000 are constants in this equation and are there simply so that the
resultant units are in Kilojoules per inch of weld (KJ/in).
Some newer machines will automatically calculate heat input for you. It is typically
provided as “total energy” in KJ. You then have to take that value and divide it by the
length of the weld in inches to get heat input in KJ/in.
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FINAL REMARKS
A properly developed welding procedure specification (WPS) should follow a proven
process to ensure quality and maximize productivity. The information in this publication
was developed to provide sufficient background information in order to make informed
decisions. Although it focuses on carbon steels, the same methodology may be used
when welding stainless steel, aluminum and other alloys. Bear in mind that different
base metals will not necessarily behave like carbon steel and you must understand their
behaviour when developing a welding procedure.
All WPSs must be approved by the engineering department or another individual
designated by the company doing the welding. This person must have a thorough
understanding of the process used to develop, test and qualify the welding procedure.
REFERENCES
The following is a list of materials that were referenced in creating this publication.
1. AWS D1.1/D1.1M:2020 Structural Welding Code - Steel
2. AWS D1.6/D1.6M:2017 Structural Welding Code - Stainless Steel
3. Welding Metallurgy and Weldability, First Edition. John C. Lippold. © 2015 John Wiley &
Sons
4. Alloy Steels, Republic Steel Corporation, 1949
5. Selecting Filler Metals: Matching Strength Criteria, Key Concepts in Welding Engineering
- Funderburk, R. Scott, PE
6. Use Undermatching Weld Metal Where Advantageous, Practical Ideas for the Design
Professional, Welding Innovation Vol. XIV, No.1, 1997 - Miller, Duane K., P.E.
7. Selecting Filler Metals: Electrodes for Stress Relieved Applications, Welding Innovation
Vol. XVIII, No.2, 2001
8. Metals and How to Weld Them - Theodore Jefferson, Gorham Woods
9. The Procedure Handbook for Arc Welding, 14t Edition
10. New Code Requirements for Calculating Heat Input- The Welding Journal, June 201o -
Theresa Melfi
11. Effect of Heat Input on Residual Stress in Submerged Arc Welds – R.K. Saxena
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Welding Answers
All rights reserved
This publication or any part thereof must not be reproduced in any form without the written
permission of the publisher.
The information presented in this publication is for general information only. While it is believed
to be accurate, this information should not be used for any specific application without
competent professional examination and verification of its accuracy, suitability and applicability
by a licensed professional engineer or designer.
Printed in the United States of America
First Printing: January 2021
78

LEGAL DISCLAIMER
THERE ARE NO WARRANTIES SET FORTH IN THIS AGREEMENT, THESE MATERIALS ARE TO PROVIDE
GENERAL INFORMATION. THE AUTHOR MAKES NO WARRANTY WHATSOEVER REGARDING THE GOODS,
SERVICES, OR PROCEDURES, INCLUDING ANY (1) WARRANTY OF MERCHANTABILITY; (2) WARRANTY OF
FITNESS FOR A PARTICULAR PURPOSE; (3) WARRANTY OF TITLE; OR (4) WARRANTY AGAINST
INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OF A THIRD PARTY; WHETHER ARISING BY LAW,
COURSE OF DEALING, COURSE OF PERFORMANCE, USAGE OF TRADE, OR OTHERWISE. BUYER
ACKNOWLEDGES THAT IT HAS NOT RELIED ON ANY REPRESENTATION OR WARRANTY MADE BY SELLER,
OR ANY OTHER PERSON ON SELLER’S BEHALF. BUYER FURTHER ACKNOWLEDGES THAT IT MUST
FOLLOW STRUCTURAL WELDING CODES, PROPERLY QUALIFIED WELDING PROCEDURES, STATE OR
FEDERAL SAFETY STANDARDS, OR OTHER REQUIREMENTS BY LAW, AND NOTHING IN THIS DOCUMENT
SHALL SUPERSEDE THE SAME. BUYER ASSUMES FULL RESPONSIBILITY FOR COMPLIANCE WITH THE
APPLICABLE WELDING CODES OR OTHER WELDING STANDARDS AND IS STRONGLY ENCOURAGED TO
REFER TO GUIDELINES, ASSURE THE FABRICATOR HAS SKILLS NECESSARY FOR THE JOB, AND
CONDUCT ANY TESTING NECESSARY TO CONFIRM THE COMPLETENESS OF THE PROCEDURE,
AMENDING DUE TO CIRCUMSTANCES AND WHERE NECESSARY. THE FUNCTIONING AND USE OF ANY
WELDING MATERIALS IS ENTIRELY DEPENDENT ON THE KNOWLEDGE, SKILL, AND TRAINING OF THE
INDIVIDUAL USING THE MATERIALS
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