The welding machinery listed above is used in a variety of welding processes, the simplest probably being spot welding, performed with the use of a special machine. This process, along with electrode or arc welding, is used in the mass production of thin-walled metal products. Here, specially moulded pre-products are fixed onto the welding press and welded onto one another with melt-flows. In addition to the classic spot welding machine, a spot welding gun is used for big and complicated products, such as automobile bodies. In combination with industrial robots, spot welding machines can be a very efficient way to automatically bond metal products together.
MEGATRONIC Welding machine in use
Arc welding machinery
Arc welding is a process of joining one metal to another with the use of electricity, by creating enough heat to melt the metal, which, after cooling, results in the binding of the two melted metals. An arc welding machine uses a power supply to make an electric arc between the base material and the electrode, in order to melt the metals at the welding point.
A special type of arc welding is submerged arc welding. A submerged arc welding machine is used for the processing of very thick-walled workpieces, for example, large tubes or pipes. During this process, a powder made out of iron oxide is put upon the welding spot instead of using a shielding gas. This is a complicated process and the submerged welding machines should only be used by skilled workers with high qualification and experience levels. Generally, the submerged arc welding process is characterized by a very comprehensive quality control. During the different work steps in the use of a submerged arc welding machine, the fatigue strength of the welded seal is regularly checked.
Electric welding can be performed using further special types of welding machines – such as an inverter welding machine, or AC/DC welding machine. The main advantages of an inverter welding machine, when compared to the conventional one, are its small and compact size and lower power consumption.
The terms AC (Alternating Current) and DC (Direct Current) depict the polarity of the electrical current, which is being produced by a welding machine and which passes through the electrode. An AC/DC welding machine, as opposed to a conventional AC welder, has the capability of employing both alternating and direct current.
Gas welding machines are used to bring the base material to a melting point with an oxy-acetylene flame. At the same time, a filler rod is introduced that is continually being melted. This process is particularly useful for build-up welding to close up openings, unevenness or gaps in the material. A gas welding machine is also particularly applicable in the welding of cast iron. Gas shielded welding is, along with arc welding, the most widely used process. Through a continual emission of shielded gas, oxygen is prevented from reaching the welding spot, as that would result in burn holes. Gas shielded welding machines can either be hand-held or fully automatic. During this welding process, one can choose between using metal inert gas welding (using an MIG welding machine), metal active gas welding (MAG) or wolfram-inert-gas welding (WIG).
