There are many kinds of resistance welding (erw), including welding, seam welding, butt welding and bump welding.


1. Spot welding
Spot welding is a kind of resistance welding method, in which welding parts are assembled into lap joints and pressed between two cylindrical electrodes to form welding joints by melting the base metal through resistance. Spot welding is mainly used for thin plate welding.


Spot welding process:
1. Preloading to ensure good contact with the workpiece.
2. Connect the power supply to make the weld form nuggets and plastic rings.
3. Power-off forging makes the nugget cool and crystallize under pressure, forming compact welded joints without shrinkage holes and cracks.


SEAM WELDING
Seam welding is mainly used to weld the seam which is relatively regular and needs to be sealed. The thickness of the joint is usually less than 3 mm.


3. Butt welding
Butt welding is a resistance welding method, in which 35Crmo alloy pipe is welded along the whole contact surface.


Fourth, bump welding
Protrusion welding is a variant of spot welding; there are prefabricated bumps on the workpiece, and one or more blocks can be formed at one time at the joint.