Title:
WELDED METAL PART HAVING HIGH STRENGTH, EXCELLENT IN LOW TEMPERATURE CRACKING RESISTANCE, AND ITS FORMING METHOD
Document Type and Number:
Japanese Patent JP3726721
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To surely obtain a welded metal part having a tensile strength of ≥750 MPa, and besides excellent in low temperature toughness and low tempera ture cracking resistance, regarding a high strength welded steel tube or the like, which has the tensile strength of ≥750 MPa.
SOLUTION: The welded metal part contains, by mass, at least C of 0.01-0.15%, Si of 0.02-0.6%, Mn of 0.6-3.0%, P of ≤0.03%, S of ≤0.03%, Al of 0.004-0.08%, Ti of 0.003-0.03%, B of ≤0.005%, N of ≤0.01%, and Ca or Mg of ≤0.005%, as welding metal components, and besides has a weld cracking sensitivity parameter (P cm) in the range of 0.23-0.35 mass%. This welded metal part is cooled to 100°C after its welding. Preheating/post-heating, or heat- keeping is carried out so that T, the time until the welding metal part is cooled to 100°C after its welding, satisfies the formula: T[sec] ≥ exp(7.0×Pw+4.66)(Pw=P cm+HD/60).
Inventors:
Tomoaki Ikeda
Akio Yamamoto
Yamauchi Shigemichi
Nobuaki Takahashi
Masahiko Hamada
Akio Yamamoto
Yamauchi Shigemichi
Nobuaki Takahashi
Masahiko Hamada
Application Number:
JP2001215394A
Publication Date:
December 14, 2005
Filing Date:
July 16, 2001
Export Citation:
Assignee:
SUMITOMO METAL INDUSTRIES,LTD.
International Classes:
B23K9/23; B23K9/18; C22C38/00; C22C38/14; C22C38/58; (IPC1-7): B23K9/23; B23K9/18; C22C38/00; C22C38/14; C22C38/58
Domestic Patent References:
| JP2000096187A | ||||
| JP9049055A |
Attorney, Agent or Firm:
Satoshi Kumon
Kumon enjoyment
Kumon enjoyment
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