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:
Apr. 03, 2012
Filed:
Jul. 14, 2005
Tetsuro Nose, Futtsu, JP;
Kiyotaka Nakashima, Oita, JP;
Tetsuro Nose, Futtsu, JP;
Kiyotaka Nakashima, Oita, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
The present invention provides a boom and arm member of a construction machine excellent in weld zone fatigue strength and a method of improvement of its fatigue strength, that is, a boom and arm member of a construction machine superior in weld zone fatigue strength, the boom and arm member of a construction machine characterized in that toes of full penetrated weld zones of the boom and arm member have vibration strike marks, and a method of improvement of its fatigue strength. Preferably, the residual stress of the bottom surface of the vibration strike marks is a 10 MPa or higher compressive residual stress.