Master the following methods to make the product to achieve a trace-free spot welding：
1 Choice of welding method: single-sided double-point welding is used; the traditional welding method is double-sided double-point, and the feed is conducted up and down. Therefore, after welding both sides have close indentation, can not guarantee a single side without marks; single-sided double-point welding can make the current through the body of the workpiece, the other side can effectively avoid the marks, because there is no more heat input, supplemented by flat electrode support.
2 Choice of welding machine structure: Platform spot welder is used. The large platform of the platform spot welder can effectively support the working parts, increase the conductive area and dissipate heat quickly after welding, thus minimizing welding deformation and achieving trace-free spot welding.
3. Choice of welding power source: the use of medium-frequency inverter DC power source. Medium-frequency inverter DC power source has a high thermal efficiency, the same nucleus requires a shorter heating time to prevent welding deformation caused by long heating, minimize plastic deformation and achieve the effect of spot welding without traces on one side.