Common grades of stainless steel are:
1. Classification according to metallographic structure
1. Common austenitic stainless steel: (with austenitic structure at room temperature) Stainless steel, steel contains about 18% Cr, 8% to 10% Ni and C less than 0.1%, including Cr and Ni content , and is a high Cr-Ni series steel developed by adding elements such as Mo, Cu, Si, Nb, Ti, etc. , with stable austenitic structure)
Commonly used abbreviations for numerical codes of new and old grades
06Cr19Ni10 0Cr18Ni9 S30408 304
022Cr19Ni10 00Cr19Ni10 S30403 304L
06Cr25Ni20 0Cr25Ni20 S30408 310S
06Cr18Ni11Ti 0Cr18Ni10Ti S32168 321
06Cr17Ni12Mo2 0Cr1 7Ni12Mo2 S31608 316
06Cr17Ni12Mo2 00Cr17 Ni14Mo2 S31603 316L
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2. Ferritic stainless steel (stainless steel with a predominantly ferrit structuree during use. The chromium content is 11% to 30% and has a body-centered cubic crystal structure.)
Numerical code of new grade and old grade
06Cr13Al 0Cr13Al S11348
06Cr13 0Cr13 S11306
………..
3. Martensitic stainless steel (stainless steel that is dominated by a martensitic structure during use and whose mechanical properties can be adjusted by heat treatment. In simple terms, it is a type of hardenable stainless steel.)
Such as: 2Cr13, 3Cr13, 4Cr13
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4. duplex stainless steel (austenitic-ferritic - Ferritic duplex stainless steel: This is a stainless steel with approximately half austenite and ferrite structures each. When the C content is low, the Cr content is 18% to 28%, and the Ni content is 3% to 10%. Some steels also contain Mo, Cu, Si, Nb, Ti, N and other el.alloy elements)
New grade code
0.22Cr22Ni5Mo3N S22253
022Cr25Ni6Mo2N S22553
022Cr23Ni5Mo3N S22053
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National reference standard: GB/T24511-2009 Pressure equipment Stainless steel plates and strips
GB/T3270-2007 Rolled stainless steel plates and strips cold
GB/T21833-2008 Duplex steel tubes
GB13296- 2007 Seamless stainless steel tubes for boilers and heat exchangers
GB /T14976-2002 Stainless steel tubes for transporting fluids
2. Classification according to foreign chemical composition: 200, 300, 400. series classification
Stainless steel 200 series: 201, 202 (chromium, nickel, manganese-austenitic stainless steel)
Stainless steel 300 series: 301, 302, 302HQ, 303, 304, 305, 304L, 304F, 304HC, 316, 316L, 316F, 316S, 316Ti, 310, 310S, 314, 314L, 317L , 321 (steel chrome stainless steel, nickel-austenitic)
Steel istainless steel 400 series: 410, 420, 420J2, 434, 430, 430F, 431 (ferritic and martensitic stainless steel)