In the maintenance method of welding repair, with the help of CO2 gas shielded welding, the appropriate welding method is selected by judging the length of weld at different positions. When the weld is short, it can start from the damaged periphery and gradually weld inward; When the weld crack is long, the welding is completed by spot welding.
However, in this process, it is necessary to control the weld temperature to avoid warping and deformation of the plate surface. However, when there is a large stress in the weld, double-sided welding can be chosen to increase the welding strength. At the same time, if the back surface is cracked, the thick plate on the back surface can be heated first, so that the weld seam and the thick plate can be welded externally.
When there is a thick plate inside and a long weld outside, the welds at both ends can be welded first, and then the thick plate on the back can be processed to complete the welding work. When repairing sheet metal parts, it is also necessary to eliminate the residual stress caused by welding to ensure the smoothness and smoothness of the weld.
In plastic maintenance, it mainly deals with the finishing work after the maintenance is completed. By hammering after welding, an anvil with a suitable shape can be placed on the opposite side of hammering, and the plastic maintenance work can be completed by extending outward from the protruding position. However, when there is a large area of pits, it can be further restored by hammering with a wooden hammer, and finally it can be repaired by hammering with a hand.
In the aspect of correction and maintenance, it is mainly aimed at the maintenance methods adopted when the fender of a certain part of the car is bent or extended when the car is damaged by impact. Generally, the two ends are fixed by tension and compression devices, and the length of the deformed part in the middle position is changed to operate, and the stretching and shrinking treatment is completed as soon as possible in combination with the heating operation of gas welding. In this process, if the position deformation is large, it can be treated by hammering or pad iron.
The purpose of digging and repairing is to carry out maintenance work under the condition that the automobile is seriously damaged by impact or corrosion. The main purpose of the restoration method is to restore its original shape. The main repair steps can be summarized as: determination of repair scope, replacement and treatment of formwork, positioning and welding of new plate, flattening treatment and reinforcement operation. Finally, the effective treatment of automobile body sheet metal parts is realized.