Title:
MANUFACTURING METHOD OF STEEL PIPE
Document Type and Number:
Japanese Patent JP2017113801
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a manufacturing method of a steel pipe capable of restraining reduction in strength and corrosion resistance of the steel pipe even if annealing is not executed after processing a pipe end.SOLUTION: A manufacturing method of a steel pipe by the present embodiment comprises a preparation process, a hardening and tempering process, a heating process, and a pipe end processing process. The preparation process prepares the steel pipe. The hardening and tempering process executes hardening and tempering to the steel pipe. The heating process heats the steel pipe in less than the tempering temperature after the hardening and the tempering. The pipe end processing process executes diameter-expanding or diameter-contracting process on a pipe end part of the steel pipe heated in less than the tempering temperature by using a plug or a die. The pipe end processing process is 600°C or more in the temperature of the pipe end part of the steel pipe when finishing pipe end processing by using the heated plug or die.SELECTED DRAWING: Figure 1
Inventors:
INOUE TAKAHIRO
Application Number:
JP2015255431A
Publication Date:
June 29, 2017
Filing Date:
December 25, 2015
Export Citation:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORP
International Classes:
B21D41/02; B21D37/16; B21D41/04; C21D8/10; C21D9/08; C22C38/00; C22C38/32
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Attorney, Agent or Firm:
Ascend Patent Business Corporation
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