IIW White Paper

2.

Welding industry in the world

2.1 Historical perspective: welding as problem solver Evidence suggests that the joining of metals was reasonably common around 3,000 BC , or even earlier than that, and that civilisations of the Bronze, Iron and Middle Ages worked metals together by heating and hammering to form adornments and other implements. This was the first means of welding, as opposed to brazing and soldering, and its use spread to other communities throughout Europe, the Middle East, and into SE Asia.

During the 18 th and 19 th Centuries critical advances in the applications of electricity and the creation and storage of gases were to profoundly influence welding and its capability to join metals together.

In 1800 , Sir Humphry Davy discovered that an electric arc could be produced between two carbon electrodes and in 1836 Edmund Davy was credited with the discovery of acetylene. The most significant work on new processes for the production of oxygen proved to be the fractional distillation of liquefied air which was achieved in the late 1800 s . The production of steel frommolten iron in 1860 was also another step forward since it produced a material with high strength and ductility that was compatible to the welding process. Here, at last, was a material that could be used for the construction of bridges, ships, boilers etc that would bring in a new era in the service of metals to man. In 1895 it was found that acetylene gas, when burnt with an equal volume of oxygen, gave a flame with a temperature of 3,130°C, 470°C higher than the oxy-hydrogen flame. To harness the effects of this high temperature flame a device was needed to mix the gases at high pressure and the first high-pressure oxy-acetylene torch was produced in 1900 . At first, oxy-fuel welding was one of the more popular welding methods due to its portability and relatively low cost. As the 20 th Century progressed, however, it fell out of favour for industrial applications. It was largely replaced with arc welding, as coverings (known as flux) for the electrode that stabilise the arc and shield the base material from impurities continued to be developed. The production and storage of gases were essential developments in the evolution of metal working, for cutting and welding and, with the introduction of automated welding in 1920 , in the critical role of shielding the arc from air, to protect welds from the effects of oxygen and nitrogen in the atmosphere. Porosity and brittleness were the primary problems, and the solutions that developed included the use of hydrogen, argon, and helium as welding atmospheres. In 1885 the first arc-welding machine was invented and a patent was issued to the Russian and Polish research workers, Bernodos and Olzeweski, who were working in France while Lincoln Electric in the US produced the first arc welding set for general usage in 1909 . Other variants of welding were also being developed and the Thermit welding process made its appearance around the turn of the century.

4

Through Optimum Use and Innovation of Welding and Joining Technologies

Improving Global Quality of Life