According to its composition, stainless steel can be divided into two categories: chromium stainless steel mainly based on chromium and chromium nickel stainless steel mainly based on chromium and nickel.
Stainless steel commonly used in industry is generally classified according to metallographic arrangement, which can be divided into the following five categories:
1. Martensitic stainless steel: chromium content 12% to 18%, carbon content 0.1% to 0.5% (sometimes up to 1%), common are 1Cr13, 2Cr13, 3Cr13, 4Cr13, 1Cr17Ni2, 9Cr18, 9Cr18MoV, 30Cr13Mo, etc. .
2. Ferrite stainless steel: chromium content 12% to 30%, common are 0Cr13, 0Cr17Ti, 0Cr13Si4NbRE, 1Cr17, 1Cr17Ti, 1Cr17M02Ti, 1Cr25Ti, 1Cr28 and so on.
3. Austenitic stainless steel: 12% to 25% complex content, 7% to 20% nickel content (or more than 20%), the most typical representative is 1Cr18Ni9Ti, the common ones are 00Cr18Ni10, 00Cr18Ni14Mo2Cu2, 0Cr18Ni12Mo2Ti, 0Cr18Ni18Mo2Cu2Ti, 0Cr23Ni28M03Cu3Ti, 1Cr14Mn14Ni, 2Cr13Mn9Ni4, 1Cr18Mn8Ni5N and so on.
4. Austenitic + ferritic stainless steel: similar to austenitic stainless steel, only contains a certain amount of ferrite in the arrangement, common are 0Cr21Ni5Ti, 1Cr21Ni5Ti, 1Cr18Mn10Ni5M03N, 0Cr17Mn13Mo2N, 1Cr17Mn9Ni3M03Cu2N, Cr2bNi17M03NiSiN, etc.
5. Precipitation hardening stainless steel: contains high chromium, nickel and very low carbon, common are 0Cr17Ni4Cu4Nb, 0Cr17Ni7Al, 0Cr15Ni7M02Al and so on.
The first two types are chrome stainless steel, and the last three types are chrome nickel stainless steel.