The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 21, 1980
Filed:
Oct. 25, 1977
Applicant:
Inventors:
Noriaki Matsuda, Mito, JP;
Kunio Enomoto, Ibaraki, JP;
Assignee:
Hitachi, Ltd., , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C21D / ;
U.S. Cl.
CPC ...
148127 ; 148 39 ; 148150 ; 148153 ; 148154 ; 148155 ; 148157 ;
Abstract
Disclosed is a method of heat-treating a pipe in which cooling water is passed through the pipe while the pipe is heated from the outer side thereof, so as to create a temperature differential between the outer and the inner sides of the pipe, so that the inner side of the pipe may be tension-yielded or the outer side of the pipe may be compression-yielded, thereby to generate a compressive residual stress and a tensile residual stress at the inner and the outer sides of the pipe, respectively.