Steel, steel bar and manufacturing method thereof
AssigneeBaoshan Iron & Steel Co., Ltd.
InventorsJun Zhang, Sixin Zhao, Jiaqiang Gao, Wei Wang
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Abstract
Provided is a steel comprising the following chemical composition in percentage by mass: 0.150-0.250% of C, 0.10-0.50% of Si, 0.60-1.50% of Mn, 0.30-1.20% of Cr, 0.20-0.80% of Mo, 2.00-4.00% of Ni, 0-0.10% of Nb, 0.0010-0.0050% of B, 0-0.12% of V, 0.003-0.06% of Ti, 0.01-0.08% of Al, the balance being Fe and unavoidable impurities. Also provided is a steel bar and a manufacturing method thereof. The steel bar is made from the above steel. The manufacturing method comprises the steps of smelting and casting, heating, forging or rolling, quenching, and tempering.
Claims11
A steel comprising the following chemical composition in percentage by mass:
- C:
- 0.15% to 0.24%, Sr, 0.10% to 0.50%, Mn:
- 0.60% to 1.50%, Cr, 0.30% to 1.20% Mo:
- 0.20% to 0.80%, Ni:
- 2.00% to 4.00%, Nb:
- 0% to 0.10% B:
- 0.0010% to 0.0050%, V:
- 0% to 0.12%, Ti:
- 0.003% to 0.06%, Al:
- 0.01% to 0.08%, and the balance being Fe and inevitable impurities, wherein the microstructure of the steel is tempered martensite and tempered bainite;
- and
- wherein the steel has a yield strength of ≥950 MPa, a tensile strength of ≥1150 MPa, a Charpy impact energy below −20° C. Akv of ≥75 J, an elongation rate of ≥15%, and a percentage reduction of area after fracture of ≥55%.
A steel bar comprising the following chemical composition in percentage by mass:
- C:
- 0.15% to 0.24%, Si:
- 0.10% to 0.50%, Mn:
- 0.60% to 1.50% Cr:
- 0.30% to 1.20%, Mo:
- 0.20% to 0.80%, Ni:
- 2.00% to 4.00%, Nb:
- 0% to 0.10%, B:
- 0.0010% to 0.0050% V:
- 0% to 0.12%, Ti:
- 0.003% to 0.06%, Al:
- 0.01% to 0.08%, and the balance being Fe and inevitable impurities, wherein the microstructure of the steel bar is tempered martensite and tempered bainite;
- and
- wherein the steel bar has a yield strength of ≥950 MPa, a tensile strength of ≥1150 MPa, a Charpy impact energy below −20° C. Aky of ≥75 J, an elongation rate of ≥15%, and a percentage reduction of area after fracture of ≥55%.
Dependencies are inferred from the claim text.