Defects of electric resistance welding is following below:
1) There is a lack of a reliable method for non-destructive testing, welding quality only by destructive testing process to check specimens and artifacts, as well as by a variety of monitoring techniques to ensure that.
2) Points, seam welded lap joint not only increases the weight of the structure, and because between the two plates around the nugget form an angle, resulting in a lower tensile strength and fatigue strength of the joint.
3) Power equipment, high degree of 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 the normal operation of the grid. With the development of electrode wear aerospace, electronics, automobiles, household appliances and other industries, the electric resistance welded together by the society, at the same time, the quality of resistance welding also put forward higher requirements.
