Improving Global Quality of Life

3.welding
Signifi cance of
and joining
Welding is one of the most commonly used technologies for the assembly of metallic materials,
where it ensures a metallurgical bond between two elements/parts of a given component.
Numerous welding technologies are utilised in fabrication, repair and maintenance in a wide
range of industrial applications, from steam generator to aircraft to high precision equipment, in almost
every industrial sector.
3.1 Major industrial sectors utilising welding and joining
Today, welding is used by preference in the industrial sectors which manufacture products made of weldable
materials. These are metallic materials, above all steels, aluminium, magnesium, titanium and nickel as well
as their alloys and thermoplastics. Composite materials and material compounds are increasingly playing
a major role. In this respect, welding frequently plays an essential role in product design and constitutes
an essential step in the value added at the manufacturing companies. In the particularly welding-intensive
sectors, the following average value added by welding may be assumed as the proportion of the total value
added:
Mechanical and apparatus engineering, including
Construction of metal and plastic pipelines: approx. 3 %
Metal construction: approx. 5 %
Vehicle construction (motor and rail vehicles): approx. 7 %
Shipbuilding: approx. 8 %
Aerospace construction: (incl. allied joining technologies): approx. 8 %
Although the main coverage is metals and their alloys, industry specific coverage does include challenges in
non-metallic materials joining and future directions e.g. electronics, medical devices, aerospace, polymers,
plastics and nano-joining of dissimilar materials.
The welding processes being applied and the respective degrees of mechanisation are very variable. They
are extremely dependent on the material to be processed and on the wage level in the region concerned. For
example, manual electrode welding and partially mechanised gas shielded arc welding are very widespread
in regions with low wage costs, while fully mechanised gas-shielded arc welding with robots or welding
gantries, submerged-arc welding and beam welding with a laser or electron beam tend to be the exception in
these regions. This is due to high equipment investment costs for mass production and the lower availability
of suitable specialist personnel. It must also be borne in mind, however, that even in regions with low
wage costs, the degree of automation of the joining processes being utilised increases when more stringent
requirements are placed on reproducibility and precision, e.g. with regard to the positioning of attached parts.
10 Improving Global Quality of Life Through Optimum Use and Innovation of Welding and Joining Technologies