What are the surface treatments of precision shrapnel? 'Hardware'

Precision shrapnel processing is a special process of processing materials (metal or non-metal) into parts (or semi-finished products) through cold stamping of stamping dies. Stamping is a pressure processing method that uses a mold installed on a press to apply pressure to the material at room temperature to cause separation or plastic deformation to obtain the required parts. There are cold rolling method and hot rolling method for processing precision shrapnel. The metal shrapnel wire whose diameter is less than 8 mm is generally cold-rolled, and larger than 8 mm is hot-rolled. Some precision shrapnels need to be subjected to strong pressure or shot peening after they are made, which can improve the load-bearing capacity of the precision shrapnels. Precision shrapnel is an elastic component widely used in the machinery and electronics industries. The shrapnel can produce greater elastic deformation when loaded, converting mechanical work or kinetic energy into deformation energy, and the deformation of the precision shrapnel disappears and returns to its original shape after unloading. , Transforming deformation energy into mechanical work or kinetic energy. 316L stainless steel can be used to make precision shrapnel. A very thin chromium oxide film is formed on the surface of the material, which can resist corrosion well. Pitting corrosion is a common form of obvious corrosion of stainless steel. Generally, it starts with needle-like corrosion. Due to corrosion, the corroded part turns black or dark brown. In most severely corrosive environments, the number and depth of pitting corrosion increases, giving the surface a corroded appearance. Under weak corrosion conditions, pitting corrosion itself cannot be significantly reduced from the surface, but corrosion may occur on the precision shrapnel to produce a thin film, and when the rust spots leak out, the surroundings may lose luster. Sensitization: Carbon (usually containing 0.08%) in steel is combined with chromium and precipitates at grain boundaries during heat treatment or during welding. The formed carbides cause chromium depletion in the grain boundaries, and an anti-corrosion film is formed on the grain boundaries while local grain boundary corrosion occurs, which reduces the stress corrosion resistance of the material.