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:
Feb. 05, 2002
Filed:
Dec. 08, 2000
Michael Patrick Manning, Watervliet, NY (US);
Robin Carl Schwant, Pattersonville, NY (US);
General Electric Company, Schenectady, NY (US);
Abstract
A heat treatment process is provided that produces a monoblock, low alloy steel rotor for use in low pressure steam turbines. The process includes austenitizing the rotor at a substantially uniformly applied treatment temperature of about 840° C., quenching the rotor, and then differentially tempering the rotor at different axial locations. The rotor is tempered in a furnace divided into regions by refractory boards enabling different temperatures in each divided region to be maintained. A higher than normal strength condition is achieved in one or more axial locations along the rotor by subjecting the location(s) to a lower tempering temperature. The axial location(s) being tempered at lower temperature approximate those locations less susceptible to stress corrosion cracking whereby increased strength is provided the rotor without increasing net susceptibility to stress corrosion cracking.