Steel material
AssigneeNippon Steel Corporation
InventorYusaku TOMIO
Life of this patent
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Abstract
In a steel material according to the present disclosure, the chemical composition consists of, in mass %, C: 0.20% to 0.45%, Si: 0.05 to 1.50%, Mn: 0.01 to 1.00%, P: 0.030% or less, S: 0.0100% or less, Cr 0.40 to 1.10%, Mo: 0.40 to 1.30%, V: 0.01 to 0.30%, Nb: 0.005 to 0.100%, Ti: 0.001 to 0.030%, Al: 0.005 to 0.100%, B: 0.0005 to 0.0050%, N: 0.0100% or less, and O: 0.0050% or less, with the balance being Fe and impurities. In the steel material, a grain size GS of prior-austenite grains is more than 5.0 to 30.0 μm, a yield strength σ is 862 to 965 MPa, a yield point drop Δσ is 40 MPa or more, and a yield point elongation Δε is 1.5% or more.
Claims8
A steel material having a chemical composition consisting of, in mass %,
- C:
- 0.20% to 0.45%,
- Si:
- 0.05 to 1.50%,
- Mn:
- 0.01 to 1.00%,
- P:
- 0.030% or less,
- S:
- 0.0100% or less,
- Cr:
- 0.40 to 1.10%,
- Mo:
- 0.40 to 1.30%,
- V:
- 0.01 to 0.30%,
- Nb:
- 0.005 to 0.100%,
- Ti:
- 0.001 to 0.030%,
- Al:
- 0.005 to 0.100%,
- B:
- 0.0005 to 0.0050%,
- N:
- 0.0100% or less,
- O:
- 0.0050% or less,
- W:
- 0 to 2.00%,
- Co:
- 0 to 0.20%,
- Mg:
- 0 to 0.0100%,
- Ca:
- 0 to 0.0100%,
- rare earth metal:
- 0 to 0.0100%,
- Cu:
- 0 to 0.40%,
- Ni:
- 0 to 0.20%, and
- Sn:
- 0 to 0.10%,
- with the balance being Fe and impurities,
- wherein:
- a grain size GS of prior-austenite grains is more than 5.0 to 30.0 μm,
- a yield strength σ is 862 to 965 MPa,
- a yield point drop Δσ is 40 MPa or more, and
- a yield point elongation Δε is 1.5% or more.
Dependencies are inferred from the claim text.