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US 6,203,630 B1Granted
Steel for induction quenching and machinery structural parts using the same
AssigneeDaido Tokushuko Kabushiki Kaisha
InventorsYasushi Matsumura, Yutaka Kurebayashi, Sadayuki Nakamura
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Abstract
A steel product contains, by mass %, C: 0.45 to 0.60%, Si: 0.01 to 0.15%, Mn: 0.20 to 0.60%, S: 0.012% or lower, Al: 0.015 to 0.040%, Ti: 0.005 to 0.050%, B: 0.0005 to 0.0050%, N: 0.010% or lower, O: 0.0010% or lower, and balance being Fe and unavoidable impurities. Limitations are provided to allowable maximum sizes per each sort of contained non-metallic inclusions and the number per unit area thereof. This steel may contains one kind or two kinds or more of Cr: 1.00% or lower, Mo: 0.50% or lower and Ni: 1.50 or lower.
Claims4
A steel for induction quenching comprising:
- ,by mass %,
- C:
- 0.45 to 0.60%,
- Si:
- 0.01 to 0.15%,
- Mn:
- 0.20 to 0.60%,
- S:
- 0.012% or lower,
- Al:
- 0.015 to 0.040%,
- Ti:
- 0.005 to 0.050%,
- B:
- 0.0005 to 0.0050%,
- N:
- 0.010% or lower,
- O:
- 0.0010% or lower, and
- balance being Fe and unavoidable impurities,
- wherein maximum sizes of contained non-metallic inclusions are, in terms of equivalent circular diameters, 15 μm or less in oxide based non-metallic inclusions, 5 μm or less in nitride based non-metallic inclusions, and 15 μm or less in sulfide based non-metallic inclusions respectively, and the numbers of the non-metallic inclusions of the equivalent circular diameters being 1 μm or more are 6 or less per 1 mm2 in the oxide based inclusions, 10 or less per 1 mm2 in the nitride based non-metallic inclusions, and 5 or less per 1 mm2 in the sulfide based non-metallic inclusions.
18 more elements
Dependencies are inferred from the claim text.