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:
Aug. 20, 1996
Filed:
Jan. 03, 1995
Charles P Blankenship, Jr, Niskayuna, NY (US);
Michael F Henry, Schenectady, NY (US);
General Electric Company, Schenectady, NY (US);
Abstract
A method of forging to impart a critical amount of retained strain is described for Ni-base superalloys, particularly those which comprise a mixture of .gamma. and .gamma.' phases, and most particularly those which contain at least about 40 percent by volume of .gamma.'. This forging method harnesses nucleation-limited recrystallization, a phenomenon which has been known in the past to produce uncontrolled, non-uniform Critical grain growth, to produce forged articles having a uniform average grain size in the range of about 90-120 microns. The method comprises the selection of a forging preform formed from a Ni-base superalloy. Isothermal subsolvus forging is then used to form a precursor forging which has a near-net shape. The precursor forging is then forged using relatively high strain rate techniques, such as hammer forging, hot die forging or room temperature forging, to impart all or some portion of it with a critical amount of retained strain energy. The forging is then given a final subsolvus soak and supersolvus anneal to form the uniform grain structure.