Steel grade:
In general, the steel grade for steel products is expressed in accordance with GB/T221-2000 regulations. The grade expression is composed of four parts: one is the part of grade symbol, one is the part of main element grade of alloy steel or low alloy steel or the main element grade and the indicated minimum teat requirement of carbon structural steel or high quality carbon structural steel and one is the part of excellent grade symbol, one is the part of proof of steel property difference symbol.
Part of grade symbol:
1. Grade symbol of alloy steel:
The grade symbol of alloy steel is composed of two parts: one part is the national standard symbol of steel grade, such as 20,15Cr, 22MnNb; the other part is the special requirements symbol of steel, such as C, V, Ti, Nb, M, B, ect.
2. Grade symbol of Low alloy steel:
The grade symbol of low alloy steel is expressed as the national standard grade symbol and the special requirement symbol of low alloy steel, such as the low alloy steel code 15MnV.
3. Grade symbol of Carbon structural steel or High quality carbon structural steel:
The grade symbol of carbon structural steel or high quality carbon structural steel is expressed as the national standard grade symbol and the minimum test value requirement symbol of carbon structural steel or high quality carbon structural steel, such as the code for carbon structural steel Q215 and the code for high quality carbon structural steel QStE340TM.
Part of excellent grade symbol:
The excellent grade symbol is expressed as the national standard grade symbol and the special excellent grade symbol of steel quality, such as the code for low alloy steel 15MnV with excellent plasticity.
Part of proof of steel property difference symbol:
The proof of steel property difference symbol is expressed as the national standard grade symbol and the special proof of steel property difference symbol, such as the steel grade 30CrMnTiA with medium temperature impact test.
Conclusion
In conclusion, steel grade for steel products is expressed in accordance with GB/T221-2000 regulations. The grade expression is composed of four parts: one is the part of grade symbol, one is the part of main element grade of alloy steel or low alloy steel or the main element grade and the indicated minimum teat requirement of carbon structural steel or high quality carbon structural steel and one is the part of excellent grade symbol, one is the part of proof of steel property difference symbol.
