400 series stainless steel

The 400 series stainless steel is an alloy of iron, carbon and chromium. The 400 series stainless steel contains a martensitic structure and iron elements. It is magnetic and has strong resistance to high temperature oxidation. Compared with carbon steel, its physical and mechanical properties have been further improved. And most of the 400 series stainless steel can be heat treated.

1. Composition and characteristics Commonly used 400 series stainless steel varieties include 430, 410, 420, 409L, etc., 430 stainless steel has a chromium content of 18%, which is characterized by low price, low thermal expansion coefficient, and chloride stress corrosion resistance better than 300 series stainless steel Variety; but its shortcomings are relatively obvious: the formability, weldability and tensile strength are less than the 300 series stainless steel models, so it limits its scope of use. The chromium content of 410 and 420 stainless steel is 13%, and their main feature is high hardness. 400 series stainless steel has the same chromium content in air, water and other oxidizing media, and its corrosion resistance is the same as that of 300 series stainless steel. Adding trace niobium, titanium, copper, aluminum and other elements can improve its stamping performance, welding performance, corrosion resistance and high temperature resistance.

2. Classification of steel types The 400 series stainless steels are mainly ferrite and martensite. ...

Ferritic stainless steel: The chromium content is generally 12% to 30%, usually without nickel, and sometimes contains a small amount of Mo, Ti, Nb and other elements. It is mostly used to make parts that are resistant to atmospheric, steam, water and oxidizing acid . Common models are 430 and 409L. ,

Martensitic stainless steel: The chromium content is not less than 12% (usually 12% to 18%), and the carbon content is higher. It is a hardenable stainless steel. Common models are 410, 420, 440, 436L.

3. Application range 400 series stainless steel has a very wide range of applications.

Automobile exhaust system, the main steel grades are 409L, 444, 436L, 439, 441, 429.

The inner tub of the washing machine, the main steel grades are 439, 430, 430J1

Tableware, kitchen sink, the main steel grades are 430, 420J1, 420J2, 410s.

Building roof materials, the main steel types are 445 and 446M.