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. 07, 1997
Filed:
Jul. 05, 1995
Hiroo Koide, Hitachioota, JP;
Yasumasa Tamai, Hitachi, JP;
Junichiro Morisawa, Naka-gun, JP;
Toshimi Matsumoto, Hitachinaka, JP;
Keiichi Uraki, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Disclosed is a highly reliable weld repairing method to repair a crack defect in structures and apparatus inside pressure vessels of nuclear reactors, while preventing generation of new crack defects in the structures and apparatus during the repairing. These structures and apparatus are made of any of stainless steel and Ni-base alloys, and are irradiated with high energy corpuscular ray during operating period of the reactor. The repairing method includes the steps of eliminating a region of the structure or the apparatus including a portion having the crack defect, and executing spot welding at a surface of the region continuously or interruptedly in a manner so as to form a first welded layer in a manner that each of the spot welded spots is half-overlapped with adjacent welded spots. Additionally, welding for forming at least a second layer, on the first welded layer, so that the at least a second layer is not deeper than a weld penetration thickness of the first welded layer can be performed.