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:
Mar. 05, 2013
Filed:
Jul. 02, 2010
Yuji Matsui, Hitachinaka, JP;
Masahiro Tooma, Hitachiota, JP;
Atsushi Baba, Tokai, JP;
Kouichi Kurosawa, Hitachi, JP;
Fujio Yoshikubo, Mito, JP;
Yuji Matsui, Hitachinaka, JP;
Masahiro Tooma, Hitachiota, JP;
Atsushi Baba, Tokai, JP;
Kouichi Kurosawa, Hitachi, JP;
Fujio Yoshikubo, Mito, JP;
Hitachi-GE Nuclear Energy, Ltd., Hitachi-shi, JP;
Abstract
A high-pressure water jet is injected from a nozzle scanned and a shock wave generated due to the collapse of bubbles included in the water jet is impacted on a WJP execution object. Tensile residual stress close to the surface of the WJP execution object is improved to compressive residual stress. The shock wave is detected by a pressure sensor and a shock wave generation frequency is obtained. Whether the obtained shock wave generation frequency is larger than a set value or not is decided. When the shock wave generation frequency is larger than the set value, a high-pressure pump is stopped and the injection of the water jet from the nozzle is stopped. When the shock wave generation frequency is equal to or smaller than the set value, the operation condition of the high-pressure pump is changed. The pressure of the water jet injected from the nozzle is increased and the WJP is executed for a part of the WJP execution object where the shock wave generation frequency is equal to or smaller than the set value. Improvement effect of the residual stress of the WJP execution object can be confirmed more accurately.