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Title:
METHOD FOR IMPROVING RESIDUAL STRESS IN PIPE, AND METHOD FOR CONSTRUCTION MANAGEMENT
Document Type and Number:
Japanese Patent JP2012021188
Kind Code:
A
Abstract:

To provide a method for compressing a tensile residual stress working on an inner surface in the vicinity of a pipe welded part at a <350°C construction temperature.

A step is repeated at least twice, wherein, after heating the vicinity of the pipe welded part at the <350°C construction temperature by heater heating from the outer surface, cooling water is supplied to the pipe inside to rapidly cool the inner surface. In the construction management, a temperature difference between inner and outer surfaces is evaluated based on lowering speed of the outer surface temperature when the cooling water is supplied to rapidly cool the inner surface, and on a pipe plate thickness at a temperature measuring position, and it is confirmed that a thermal stress generated by the temperature difference between the inner and outer surfaces is equal to or higher than a yield stress of a pipe material.


Inventors:
AOIKE SATOSHI
TSURUKI MASAKI
OKIDO SHINOBU
FUKUDA YUKA
ORITANI NAOHIKO
SUGANO SATOSHI
Application Number:
JP2010159270A
Publication Date:
February 02, 2012
Filing Date:
July 14, 2010
Export Citation:
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Assignee:
HITACHI GE NUCLEAR ENERGY LTD
International Classes:
C21D9/50; B23K31/00; C21D9/08; B23K101/06
Domestic Patent References:
JP2005023354A2005-01-27
JP2005320626A2005-11-17
JP2005023354A2005-01-27
Attorney, Agent or Firm:
Manabu Inoue
Yuji Toda
Takahiro Watanabe
Shigemi Iwasaki