Title:
ELECTRIC RESISTANCE WELDED STEEL PIPE FOR MECHANICAL STRUCTURE COMPONENT AND MANUFACTURING METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2022/085152
Kind Code:
A1
Abstract:
Provided is an electric resistance welded steel pipe for a mechanical structure component, the steel pipe including a machining part X corresponding to at least one of a drawing machining part and a steel pipe bending machining part, wherein: the machining part X includes a base material part and an electric resistance welded part; the chemical composition of the base material part includes, in mass percentages, 0.150-0.230% of C, 0-0.50% of Si, 0.50-1.65% of Mn, 0.010-0.050% of Nb, 0.10-0.60% of Mo, and 0.005-0.060% of Al, the remainder being Fe and impurities; the area ratio of tempered bainite to the overall microstructure of the base material part is at least 80%; the tensile strength of the base material part is 850-1,000 MPa; a yield elongation of at least 0.2% is observed in tensile testing of the base material part; and the ratio of the Vickers hardness of a location at a depth of 50 μm from the outer surface of the base material part to the Vickers hardness of a thick middle part of the base material part is at least 95%.
Inventors:
IMAMURA HIROHITO (JP)
Application Number:
PCT/JP2020/039712
Publication Date:
April 28, 2022
Filing Date:
October 22, 2020
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
International Classes:
C21D8/10; C21D9/08; C22C38/00; C22C38/58
Foreign References:
| JP2009270142A | 2009-11-19 | |||
| JP2009203492A | 2009-09-10 | |||
| JP2008255397A | 2008-10-23 | |||
| JP2007262491A | 2007-10-11 | |||
| JPH07216505A | 1995-08-15 |
Attorney, Agent or Firm:
TAIYO, NAKAJIMA & KATO (JP)
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