Automotive sheet metal is a processing method of automobile maintenance, also called cold working. To put it bluntly, if the appearance of the car body is damaged or deformed, the sheet metal process is needed.
Automobile collision repair has developed from the initial "smashing and welding repair" to the secondary manufacturing and assembly of the car body. The repair of the hit vehicle is no longer a simple automotive sheet metal jump, and the quality of repair can not be observed only by naked eyes. Maintenance personnel should not only know the technical parameters and dimensions of the car body, but also master the material characteristics of the car body. Stress characteristics can convey the deformation trend and stress points of the car body, as well as the production process of the car body, such as welding process. On the basis of mastering this knowledge, maintenance personnel should also use advanced measuring tools and accurate three-dimensional measurement of the car body to judge the direct or indirect damage and deformation of the car body and the hidden dangers caused by the deformation of the car body, and formulate a complete car body repair plan. Then, with the help of correct maintenance technology, accurately weigh the three-dimensional size data of each key point, restore the key points of the car body to the original position, and restore the damaged car body to the factory state.
In automobile manufacturing and maintenance, the shapes of many sheet metal structures are very complicated. In order to avoid the difficulty of sheet metal, sheet metal materials must have good technological performance requirements, namely:
1. Sheet metal materials must have good plasticity. It has the ability to produce permanent deformation without being destroyed by external forces. For cold-worked parts, good cold plasticity is needed, such as stamping parts of automobile parts; For hot working parts, good thermoplasticity is needed, such as hot forging spring steel plate, hot riveting rivet, etc.
2. Materials with good weldability have high welding strength and low cracking tendency.
3. Low price, economy and practicality. For any part of a car, economy should be considered when working conditions are met. If black metal can be used, non-ferrous metal is not needed; If you can use non-ferrous metals, never use precious metals. The service life of automotive sheet metal parts should be compatible with that of other automobile parts.
4. Good chemical stability. Most automobile panels work in the open air and often come into contact with water and steam, especially mufflers, which often work in high temperature and corrosive gases. This requires that sheet metal parts must have good chemical stability, not only strong corrosion and rust resistance at room temperature, but also no corrosion or deformation at high temperature or under the sun.
5. Good dimensional accuracy and internal quality of the plate. The dimensional accuracy and internal quality of sheet metal have great influence on sheet metal processing, especially on molded parts.