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:
Sep. 12, 2000
Filed:
Mar. 25, 1998
Gerald Richard Crawmer, Clifton Park, NY (US);
John Francis Nolan, Latham, NY (US);
General Electric Co., Schenectady, NY (US);
Abstract
A method for weld repairing an article formed of a low-alloy steel, such as a steam turbine component. The method generally includes the step of depositing a first weld repair (14) on a surface of the article, during which a hard heat-affected zone (HAZ) (18) having a fine grain size is formed in the article beneath the surface on which the weld repair (14) is deposited. The first weld repair (14) and at least a portion of the HAZ (18) adjacent the first weld repair (14) are then locally heat treated at a temperature above a critical temperature A.sub.1 of the alloy from which the article is formed. As a result of this localized heat treatment, the original grain structures of the first weld repair (14) and the HAZ (18) are entirely replaced with a fine-grain structure with acceptable hardness. Thereafter, at least one additional weld repair layer (16) is deposited on the first weld repair (14). The first weld repair (14) is intentionally formed to have a sufficient thickness to avoid formation of additional HAZ in the surface of the article as the additional weld repair layer (16) is deposited. Without a post-weld heat treatment of the additional weld repair layer (16) or the article as a whole, the method yields a repair weld (12) that exhibits properties that are comparable to and can even exceed that of the base material (10) of the article.