Electric resistance welded steel pipe or tube
AssigneeJfe Steel Corporation
InventorsYoshikazu Kawabata, Makio Gunji
Life of this patent
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Abstract
An electric resistance welded steel pipe or tube comprises: a base metal being a steel sheet having a specific chemical composition and an electric resistance weld portion having a bond width of 40×10−6 m or more and 120×10−6 m or less, wherein C0-C1 is 0.05 mass % or less, where C0-C1 is a difference between C1 in mass % which is a minimum C content of the electric resistance weld portion and Co in mass % which is a C content of the steel sheet, and a depth of a total decarburized layer in each of an inner surface layer and an outer surface layer of the electric resistance welded steel pipe or tube is 50×10−6 m or less.
Claims4
An electric resistance welded steel pipe or tube comprising:
- a base metal being a steel sheet having a chemical composition containing, in mass %,
- C:
- 0.15% to 0.40%,
- Si:
- 0.05% to 0.50%,
- Mn:
- 0.30% to 2.00%,
- Al:
- 0.01% to 0.10%,
- Ti:
- 0.001% to 0.04%,
- B:
- 0.0005% to 0.0050%, and
- N:
- 0.0010% to 0.0100%,
- with a balance consisting of Fe and inevitable impurities, a Ti content and a N content satisfying the following Formula (1),
- (N/14)<(Ti/47.9) (1)
- where N is the N content in mass % and Ti is the Ti content in mass %, and
- an electric resistance weld portion having a bond width of 40×10−6 m or more and 120×10−6 m or less, wherein
- C0-C15 0.05 mass % or less, where C0-C1 is a difference between C1 in mass % which is a minimum C content of the electric resistance weld portion and C0 in mass % which is a C content of the steel sheet, and
- a depth of a total decarburized layer in each of an inner surface layer and an outer surface layer of the electric resistance welded steel pipe or tube is 50×10−6 m or less,
- wherein the electric resistance welded steel pipe or tube is normalized.
An electric resistance welded steel pipe or tube comprising:
- a base metal being a steel sheet having a chemical composition containing, in mass %,
- C:
- 0.15% to 0.40%,
- Si:
- 0.05% to 0.50%,
- Mn:
- 0.30% to 2.00%,
- Al:
- 0.01% to 0.10%,
- Ti:
- 0.001% to 0.04%,
- B:
- 0.0005% to 0.0050%, and
- N:
- 0.0010% to 0.0100%,
- with a balance consisting of Fe and inevitable impurities, a Ti content and a N content satisfying the following Formula (1),
- (N/14)<(Ti/47.9) (1)
- where N is the N content in mass % and Ti is the Ti content in mass %, and
- an electric resistance weld portion having a bond width of 40×10−6 m or more and 120×10−6 m or less, wherein
- C0-C1 is 0.05 mass % or less, where C0-C1 is a difference between C1 in mass % which is a minimum C content of the electric resistance weld portion and C0 in mass % which is a C content of the steel sheet, and
- a depth of a total decarburized layer in each of an inner surface layer and an outer surface layer of the electric resistance welded steel pipe or tube is 50×10−6 m or less.
Dependencies are inferred from the claim text.