What is welding technology?
Welding refers to the uniting or fusing of pieces by using heat and/or compression so that the pieces form a continuum. The source of heat in welding is usually an arc flame produced by the electricity of the welding power source. Arc-based welding is called arc welding.
Usually, a filler metal is, however, melted into the welding seam, or weld, either using a wire feeder through the welding gun (MIG/MAG welding) or by using a manual-feed welding electrode. In this scenario, the filler metal must have approximately the same melting point as the material welded.
Before beginning with the welding, the edges of the weld pieces are shaped into a suitable welding groove, for example, a V groove. As the welding progresses, the arc fuses together the edges of the groove and the filler, creating a molten weld pool.
For the weld to be durable, the molten weld pool must be protected from oxygenation and effects of the surrounding air, for example with shielding gases or slag. The shielding gas is fed into the molten weld pool with the welding torch. The welding electrode is also coated with a material that produces shielding gas and slag over the molten weld pool.
Welding methods can be classified by the method used in producing the welding heat and the way the filler material is fed into the weld. The welding method used is selected based on the materials to be welded and the material thickness, the required production efficiency, and the desired visual quality of the weld.
The most commonly used welding methods are MIG/MAG welding, TIG welding, and stick (manual metal arc) welding. The oldest, most known, and still fairly common process is MMA manual metal arc welding, which is commonly used in installation workplaces and outdoor sites that demand good reachability.
The slower TIG welding method allows for producing extremely fine welding results, and therefore it is used in welds that will be seen or that require particular accuracy.
MIG/MAG welding is a versatile welding method, in which the filler material need not be separately fed into the molten weld. Instead, the wire runs through the welding gun surrounded by the shielding gas straight into the molten weld.
MIG WELDING TECHNIQUE
In MIG/MAG welding, the welder’s tool is a welding gun. It is used to introduce the filler material wire, shielding gas, and the required welding current to the workpiece. The most important issues related to MIG/MAG welding are the welding position, welding gun angle, wire stick-out length, welding speed, and the shape of the molten weld pool.
The arc is ignited with a trigger in the gun, and the gun is then moved at a steady welding speed along the weld groove. The formation of the molten weld must be observed. The position and distance of the welding gun relative to the workpiece must be maintained constant.
MIG /MAG welding equipment is typically comprised of a power source, wire feeder, grounding cable, welding gun, optional liquid cooling unit, and a shielding gas tank or gas network interface.