Steel encyclopedia - Classification of steel -400 series stainless steel

400 series stainless steel is an alloy of iron, carbon and chromium. Because it does not contain nickel, so it is a section of nickel stainless steel, also known as stainless iron. 400 series stainless steel has normal magnetic properties due to its martensitic structure and iron.

400 series stainless steel has a strong resistance to high temperature oxidation, compared with carbon steel, its physical and mechanical properties are further improved. Most 400 series stainless steels can be heat treated.

Commonly used 400 series of stainless steel varieties 430, 410, 420, 409L, etc., 430 stainless steel usage is the largest. 430 stainless steel chromium content is 18%, its characteristics are cheap, small thermal expansion coefficient, chloride stress corrosion resistance is better than 300 series of stainless steel varieties; However, its shortcomings are relatively obvious: formability, weldability and tensile strength are less than 300 series stainless steel models, so the scope of its use is limited. 410, 420 stainless steel chromium content of 13%, their main characteristic is high hardness.

400 series stainless steel in the same chromium content, in the atmosphere, fresh water and nitric acid so oxidizing medium, its corrosion resistance and 300 series stainless steel is the same, and better than 200 series stainless steel. Adding trace niobium, titanium, copper, aluminum and other elements can improve its deep drawing performance, weldability, corrosion resistance and high temperature strength, and can partially replace 300 series stainless steel.

At present, 400 series stainless steel is widely used in automobile exhaust pipe, elevator, washing machine cylinder, kitchen utensils, household appliances, medical equipment, water heater, roof plate, curtain wall and power plant equipment and other industries.