4
Improving Global Quality of Life
Through Optimum Use and Innovation of Welding and Joining Technologies
Welding industry
in the world
2.
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.
