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. 30, 1976
Filed:
Mar. 20, 1975
Saburo Usami, Hitachi, JA;
Hitachi, Ltd., Tokyo, JA;
Abstract
In a weld for two metals having adjacent surfaces with a welded zone having deposited weld metal and an unwelded zone with a stress concentration between the two zones that would normally drastically decrease the fatigue strength, the fatigue strength is greatly improved by applying a preliminary load on the welds zone by the application of a fluid pressure between the unwelded adjacent surfaces to directly stress the stress concentration transition area. Preferably, the stress intensity factor for the fluid pressure at the stress concentration zone will be higher than the combined tensile and flexural stress intensity factors so that there will be localized yielding at the stress concentration area without damaging the remainder of the weld. The metal and/or fluid is heated to avoid fracture and further to vaporize any liquid remaining once the fluid pressure is removed.