Creep-resistant steel

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.

Dependencies are inferred from the claim text.