The resistance welding machine uses the resistance heat effect generated by the electric current passing through the contact surface of the workpiece and the adjacent area to heat it to a molten or plastic state to form a metal bond. There are four main types of resistance welding methods: spot welding, seam welding, projection welding and butt welding.
The characteristics of resistance welding machines are as follows.
1. The resistance welding machine uses the resistance heat generated by the weldment, which is conducted from the high temperature zone to the low temperature zone, to heat and melt the metal to achieve welding. It belongs to the internal distribution of energy.
2. The weld seam of resistance welding machine solidifies or collects crystallization under pressure, which belongs to the category of pressure welding and has the characteristics of forging and pressing.
3. Due to the concentration of welding heat, short heating time, small heat-affected zone, small welding deformation and stress. Therefore, calibration and heat treatment are not required after welding.
4. Generally no welding materials such as welding wire, flux and gas protection are needed, and the welding cost is low.
5. Resistance welding machine nucleus is always surrounded by solid metal, molten metal and air isolation, welding process is relatively simple.
6. Simple operation, convenient mechanization and automation, and good labor conditions.
7. High productivity, can be arranged with other processes in the assembly welding line.