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:
Sep. 23, 2009
Mohamed Nazmy, Fislisbach, CH;
Markus Staubli, Dottikon, CH;
Andreas Kuenzler, Baden, CH;
ALSTOM Technology Ltd., Baden, CH;
Abstract
A creep-resistant steel is characterized by the following chemical composition (values in % by weight): 9.0 to 12.0 Cr, 0.1 to 0.5 Mn, 2.3 to 3 Ni, 1.5 to 2.0 Mo, 0.1 to 0.4 V, 0.01 to 0.06 Nb, 0.08 to 0.16 C, 0.02 to 0.08 N, 0.004 to 0.012 B, 0.001 to 2 Ta, 0.001 to 0.5 La, 0.0001 to 1 Pd, maximum 0.005 P, maximum 0.005 S, maximum 0.05 Si, maximum 0.005 Sn, the remainder iron and unavoidable impurities. This steel is distinguished, as compared with commercial steels, by a greatly improved creep behavior at temperatures of 550° C. and above. Moreover, it has an improved resistance to embrittlement during long-term aging and comparatively high toughness. The steel is advantageously used as a material for gas turbine rotors which are exposed to high inlet temperatures in order to increase the efficiency of the gas turbine, but is also used for steam turbines.