Patent ID: 6773519
Filing Date: 2004-08-10
Classification: C21D,C22C,F01D

Abstract:
A high pressure and low pressure integrated turbine rotor comprising an alloy having an alloy composition comprising:carbon in an amount of 0.20 to 0.35% by weight, silicon in an amount of 0.15% by weight or less, manganese in an amount of 0.05 to 1.0% by weight, nickel in an amount of 0.3 to 1.5% by weight, chromium in an amount of 1.0 to 3.0% by weight, molybdenum in an amount of 0.5 to 1.5% by weight, vanadium in an amount of 0.1 to 0.3% by weight, phosphorus in an amount not larger than 0.012% by weight or substantially no phosphorus, sulfur in an amount not larger than 0.005% by weight or substantially no sulfur, copper in an amount not larger than 0.15% by weight or substantially no copper, aluminum in an amount not larger than 0.01% by weight or substantially no aluminum, arsenic in an amount not larger than 0.01% by weight or substantially no arsenic, tin in an amount not larger than 0.01% by weight or substantially no tin, and antimony in an amount not larger than 0.003% by weight or substantially no antimony, the balance being iron and unavoidable impurities, except that the alloy composition contains no niobium, wherein a high-pressure part of the high pressure and low pressure integrated turbine rotor has a creep rupture time of 3000 hours or longer in a creep rupture test on an unnotched test piece under conditions of temperature of 6000Â° C. and of stress of 147 MPa, and a creep rupture time of 10000 hours or longer in a creep rupture test on a notched test piece under said conditions.