The method of electric resistance welding is one of the most popular in the case of joining elements made of metals. Welding machines designed for this purpose are used to carry out the works.
Electric resistance welding is divided into:
- point (one-sided and two-sided)
- butt (short-circuit, spark)
- linear (overlap, linear-butt)
Welding takes place in three phases. There are three phases:
Phase 1 - two or more elements to be joined are subjected to the clamping force of the electrodes, then they are pressed together and a high current is applied, which causes heat to be released on the surface of the elements and a plastic metal is formed - this zone is called the core of the weld.
Phase 2 - the weld nucleus grows larger in order to obtain a joint with adequate strength, distortions also appear, which is a normal side effect.
Phase 3 - when the power supply is cut off, the weld nucleus has the maximum size, but the elements are still pressed with electrodes, which causes the metal solidification process and the connection of elements to begin.