Low specific gravity steel for forging use excellent in machineability
AssigneeNippon Steel & Sumitomo Metal Corporation
InventorsHiromasa Takada, Suguru Yoshida
Life of this patent
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Abstract
Steel for forging having high strength and superior machinability due to controlled cooling immediately after shaping by hot forging followed by tempering and having a lower specific gravity than ordinary steel for forging use, the steel containing C: 0.05 to 0.50%, Si: 0.01 to 1.50%, Mn: 3.0 to 7.0%, P: 0.001 to 0.050%, S: 0.020 to 0.200%, Al: 3.0 to 6.0%, Cr: 0.01 to 1.00%, and N: 0.0040 to 0.0200% and having a balance of Fe and unavoidable impurities.
Claims4
A steel for forging consisting of, by mass%,
- C:
- 0.05 to 0.50%,
- Si:
- 0.01 to 1.50%,
- Mn:
- 5.1 to 5.5%,
- P:
- 0.001 to 0.050%,
- S:
- 0.020 to 0.200%,
- Al:
- 3.6 to 6.0%,
- Cr:
- 0.01 to 0.20%,
- N:
- 0.0040 to 0.0200%, and
- having a balance of Fe and unavoidable impurities,
- wherein the specific gravity of the steel is 7.44 or less.
A steel for forging consisting of, by mass%,
- C:
- 0.05 to 0.50%,
- Si:
- 0.01 to 1.50%,
- Mn:
- 5.1 to 5.5%,
- P:
- 0.001 to 0.050%,
- S:
- 0.020 to 0.200%,
- Al:
- 3.6 to 6.0%,
- Cr:
- 0.01 to 0.20%,
- N:
- 0.0040 to 0.0200%, and
- one or more of
- V:
- 0.05 to 0.30%,
- Nb:
- 0.05 to 0.30%,
- Ti:
- 0.005 to 0.050%, and
- having a balance of Fe and unavoidable impurities,
- wherein the specific gravity of the steel is 7.44 or less.
A forged product obtained by hot-forging a steel ingot consisting of, by mass%,
- C:
- 0.05 to 0.50%,
- Si:
- 0.01 to 1.50%,
- Mn:
- 5.1 to 7.0%,
- P:
- 0.001 to 0.050%,
- S:
- 0.020 to 0.200%,
- Al:
- 3.0 to 6.0%,
- Cr:
- 0.01 to 0.20%,
- N:
- 0.0040 to 0.0200%, and
- having a balance of Fe and unavoidable impurities,
- wherein −3.3×% C+0.2×% Si−0.31×% Mn+0.17×% Al+0.62≤0 (formula 1), and
- wherein the specific gravity of the steel is 7.44 or less.
A forged product obtained by hot-forging a steel ingot consisting of, by mass%,
- C:
- 0.05 to 0.50%,
- Si:
- 0.01 to 1.50%,
- Mn:
- 5.1 to 7.0%,
- P:
- 0.001 to 0.050%,
- S:
- 0.020 to 0.200%,
- Al:
- 3.0 to 6.0%,
- Cr:
- 0.01 to 0.20%,
- N:
- 0.0040 to 0.0200%, and
- one or more of
- V:
- 0.05 to 0.30%,
- Nb:
- 0.05 to 0.30%,
- Ti:
- 0.005 to 0.050%, and
- having a balance of Fe and unavoidable impurities,
- wherein −3.3×% C+0.2×% Si−0.31×% Mn+0.17×% Al+0.62≤0 (formula 1), and
- wherein the specific gravity of the steel is 7.44 or less.
Dependencies are inferred from the claim text.