Electric resistance welding (ERW Pipe
) refers to a method that uses a strong current to pass through the contact point between the electrode and the workpiece, and heat is generated by the contact resistance to achieve welding. A certain amount of pressure must be applied to the electrode and the workpiece during welding. Resistance welding is divided into spot welding, projection welding, seam welding, butt welding and resistance bolt welding. Due to the short power-on time, high production efficiency and stable welding quality. Therefore, it is used in mass production occasions for welding thin metal plates with a thickness of less than 3mm. Butt welding can also be used for butt welding of cross-section metal plates (such as rail welding), but the capacity of the welding machine is as high as 1000kV.A or more.
Resistance welding is a type of welding method that uses resistance heat as the energy source, including electroslag welding using slag resistance heat as the energy source and resistance welding using solid resistance heat as the energy source.
Resistance welding is generally a welding method in which the workpiece is placed under a certain electrode pressure and the contact surface between the two workpieces is melted by the resistance heat generated when the current passes through the workpiece to realize the connection. Usually use a larger current. In order to prevent arcing on the contact surfaces and to forge the weld metal, pressure must always be applied during the welding process. When performing this type of resistance welding, the surface quality of the welded workpiece is of paramount importance for obtaining stable welding quality. Therefore, the contact surface between the electrode and the workpiece and between the workpiece and the workpiece must be cleaned before welding.