From the Sumerians to the Lasers
In the beginning, there was fire! This primary source of energy was the only usable source for this purpose as well. The connection of two metallic work pieces was accomplished by means of forge welding. The two parts were heated in fire and then forged together.
The beginning of industrialisation generated a high demand for safe and economical production processes. Further processes became feasible due to technological progress in the 19th century. For instance, acetylene was discovered and gas welding was invented in connection with air liquefaction according to Carl von Linde in 1892.
In order to promote arc welding – the electric arc had already been discovered in 1782 – first of all efficient current sources had to be designed. The breakthrough in arc welding, i.e. broad industrial application, only followed about 1930.
Due to the development in ship and vehicle construction, welding processes were required that met the requirements in respect of strength and economy. The number of welding processes increased from two in 1800 to five around 1900. By 1950 there were more than twenty; today there are more than forty.
You can see a short summary of the historical development of welding technology on the following page.
approx. 3200 b.C. hardbrazed ewellery of the Sumerian
approx.1500 b.C. first discovery of fire and hammer welded parts
Current developments and research trends:
Hybrid welding processes (Laser/MIG; Laser/WIG; Laser/plasma)
Further development of the plasma-MIG process
Commercial application of friction stir welding
Areas of Welding Engineering
The sectors, in which the welding technology is applied, are very complex. These industries gain by means of welding technology approx. € 27 • 109.
Concerning the vehicle industry welding technology is highly represented in several varieties. With the amount of produced vehicles it receives the highest amounts of money. Even a calling card which is nowadays a part of every-day life represents the possibilities of welding technology.
Definitions of Welding in Accordance with EN 14610
EN 14610 defines metal welding processes, differentiates in accordance with physical properties and the relevant energy carrier.
The following classifications and definitions are applied:
Metal welding processes: Process that connects metal(s) under application of heat and/or pressure in such a manner that the result is a continuous internal structure of the connected metal and/or metals.
Filler metal with a melting temperature of the same range of magnitude as the connected basic material(s) can be added. The result of welding is the welding seam.
This definition includes coating.
Pressure welding: Welding during which sufficient external force is applied in order to effect more or less severe plastic deformation at both mating surfaces, commonly without addition of filler metal.
The work pieces are normally – however not necessarily – heated at the mating surfaces in order to enable or facilitate the connection.
Fusion welding: Welding without application of external force during which the mating surface(s) must be partially melted; molten filler metal is commonly – however not necessarily – added.