Material selection requirements for stainless steel fasteners

The requirements for the selection of stainless steel fasteners are mainly stainless steel. Stainless steel is steel that is not easy to rust. In fact, some stainless steels have both rust and acid resistance (corrosion resistance). The stainless steel's rust and corrosion resistance is due to the formation of a chromium-rich oxide film (passivation film) on its surface. This rust and corrosion resistance are relative. The test shows that the corrosion resistance of steel in the weak medium such as atmosphere and water and the oxidizing medium such as nitric acid increases with the increase of the water content of chromium in the steel. When the chromium content reaches a certain percentage, the corrosion resistance of the steel occurs. Mutations, from rust to rust, from corrosion to corrosion. There are many methods for classifying stainless steel. According to the structure of the structure at room temperature, there are martensite, austenitic, ferrite and duplex stainless steel; according to the main chemical composition, can be basically divided into two systems: chromium stainless steel and chromium nickel stainless steel; There are nitric acid resistant stainless steel, sulfuric acid resistant stainless steel, seawater resistant stainless steel standard parts, etc. According to the type of corrosion resistance, it can be divided into pitting resistant stainless steel, stress corrosion resistant stainless steel, intergranular corrosion resistant stainless steel, etc. It is non-magnetic stainless steel, free-cutting stainless steel, low-temperature stainless steel, high-strength stainless steel, etc. Due to its excellent corrosion resistance, formability, compatibility and toughness over a wide temperature range, stainless steel is widely used in heavy industry, light industry, household goods industry and architectural decoration industries. .