1.the method of grinding the welding head When the welding head is not strong or the wire is brought up, the first should be to grind the welding head, not to increase the parameters. When grinding the welding head, be careful not to use too much force to grind, only need to use a grinding disc or W5 Use fine sandpaper to lightly polish the bottom of the welding head with one or two strokes. 2.Do not loosen the welding head frequently There is insulating glue in the middle of the welding head and then loosening it will affect the contact position of the welding heads on both sides, causing the welding effect to be very bad. Therefore, it is strongly recommended that the welding head is installed and used until the welding head can not be used before taking it out. Do not frequently disassemble and assemble the welding head in the middle. 3.The clamping part of the welding head clamp should be clean Because the welding uses a large current, the reason that a large parameter is often required is that the center of the welding head clamped by the welding head clamp is very dirty, which seriously affects the flow of current. Therefore, it is recommended to clean the area once a month.

Due to the high hardness and high brittleness of the high-strength automotive sheet itself, there is a greater tendency for interface fracture failure during the spot welding process, by studying the welding performance of automobile plates under different spot welding process parameters, the fracture failure of high-strength automobile plate spot welding joints is divided into three categories,It is typical failure mode of spot welded joints for automotive plates, high-strength automotive plate spot welded joint are mainly divided into three failure modes: interface fracture, fusion line fracture and heat- affected zone fracture.Among, the interface mode of (a) is interface fracture, the fracture of the spot welded joint has penetrated the entire fusion zone, and the macroscopic fracture is relatively flat; (b) the interface mode is fusion line fracture. The fracture position of the spot welded joint is at the fusion line. The macroscopic morphology of the fracture indicates that the fracture is not flat, but consistent with the direction of tensile and shear forces and formed with the plane of the steel plate. Deflection at a certain angle; The interface fracture mode of (c) is heat-affected zone fracture. The fracture position of the spot welded joint is located in the softening zone, that is, at the junction of the base material zone of the heat-affected zone, and the nugget is completely pulled out.