Improving Global Quality of Life
Improving Global Quality of Life
Improving Global Quality of Life
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Welding industry 2.in the world<br />
2.1 Historical perspective: welding as problem solver<br />
Evidence suggests that the joining <strong>of</strong> metals was reasonably common around 3,000 BC, or even earlier<br />
than that, and that civilisations <strong>of</strong> the Bronze, Iron and Middle Ages worked metals together by heating and<br />
hammering to form adornments and other implements. This was the first means <strong>of</strong> welding, as opposed to<br />
brazing and soldering, and its use spread to other communities throughout Europe, the Middle East, and<br />
into SE Asia.<br />
During the 18 th and 19 th Centuries critical advances in the applications <strong>of</strong> electricity and the creation and<br />
storage <strong>of</strong> gases were to pr<strong>of</strong>oundly influence welding and its capability to join metals together.<br />
In 1800, Sir Humphry Davy discovered that an electric arc could be produced between two carbon electrodes<br />
and in 1836 Edmund Davy was credited with the discovery <strong>of</strong> acetylene. The most significant work on new<br />
processes for the production <strong>of</strong> oxygen proved to be the fractional distillation <strong>of</strong> liquefied air which was<br />
achieved in the late 1800s.<br />
The production <strong>of</strong> steel from molten iron in 1860 was also another step forward since it produced a material<br />
with high strength and ductility that was compatible to the welding process. Here, at last, was a material<br />
that could be used for the construction <strong>of</strong> bridges, ships, boilers etc that would bring in a new era in the<br />
service <strong>of</strong> metals to man.<br />
In 1895 it was found that acetylene gas, when burnt with an equal volume <strong>of</strong> oxygen, gave a flame with<br />
a temperature <strong>of</strong> 3,130°C, 470°C higher than the oxy-hydrogen flame. To harness the effects <strong>of</strong> this high<br />
temperature flame a device was needed to mix the gases at high pressure and the first high-pressure<br />
oxy-acetylene torch was produced in 1900.<br />
At first, oxy-fuel welding was one <strong>of</strong> the more popular welding methods due to its portability and relatively<br />
low cost. As the 20 th Century progressed, however, it fell out <strong>of</strong> favour for industrial applications. It was<br />
largely replaced with arc welding, as coverings (known as flux) for the electrode that stabilise the arc and<br />
shield the base material from impurities continued to be developed.<br />
The production and storage <strong>of</strong> gases were essential developments in the evolution <strong>of</strong> metal working, for<br />
cutting and welding and, with the introduction <strong>of</strong> automated welding in 1920, in the critical role <strong>of</strong> shielding<br />
the arc from air, to protect welds from the effects <strong>of</strong> oxygen and nitrogen in the atmosphere. Porosity and<br />
brittleness were the primary problems, and the solutions that developed included the use <strong>of</strong> hydrogen,<br />
argon, and helium as welding atmospheres.<br />
In 1885 the first arc-welding machine was invented and a patent was issued to the Russian and Polish<br />
research workers, Bernodos and Olzeweski, who were working in France while Lincoln Electric in the US<br />
produced the first arc welding set for general usage in 1909. Other variants <strong>of</strong> welding were also being<br />
developed and the Thermit welding process made its appearance around the turn <strong>of</strong> the century.<br />
4 <strong>Improving</strong> <strong>Global</strong> <strong>Quality</strong> <strong>of</strong> <strong>Life</strong> Through Optimum Use and Innovation <strong>of</strong> Welding and Joining Technologies