Electric resistance welding method is a combination of the workpiece to exert pressure through the electrode, the use of current through the resistor thermal contact surfaces and adjacent areas generated by joint welding.
Advantage of Electric resistance welding
1, nugget, always surrounded by a plastic ring, molten metal and air separation, metallurgy process is simple.
2, the heating time is short, heat concentration, it is a small heat-affected zone, deformation and stress is also small, usually do not have to arrange correction after welding and heat treatment processes.
3, no wires, rods and other filler metals, as well as oxygen, acetylene, hydrogen, such as welding materials, welding low cost.
4, simple operation, easy to implement mechanization and automation, improved working conditions.
5, high productivity, and no noise and harmful gases, in mass production, and other manufacturing processes can be edited together to the assembly line. But due to flash butt welding sparks splash, need to be isolated.
Shortcoming of electric resistance welding
1, there is a lack of reliable non-destructive testing methods, the quality of the welding process can only rely on destructive test specimens and artifacts to examine and rely on a variety of monitoring techniques to ensure that.
2, point seam welding lap joint not only increases the weight of the structure, and because the two plates nugget formed around an angle, so that the tensile strength and fatigue strength of the joint were low.
3, power equipment, high mechanization and automation, so that the higher cost of equipment, maintenance more difficult, and the commonly used high-power single-phase AC welder is not conducive to balanced operation of the grid.
