Patent ID: 7238005
Filing Date: 2007-07-03
Classification: C22C,F01K

Abstract:
1. A steam turbine power plant comprising a high-pressure turbine, an intermediate-pressure turbine and a low-pressure turbine, the intermediate-pressure turbine being separated into a high-temperature, intermediate-pressure turbine into which high-temperature steam having steam exhausted from the high-pressure turbine reheated to 650° C. or more is introduced and a low-temperature, intermediate-pressure turbine into which steam exhausted from the high-temperature, intermediate-pressure turbine is introduced, wherein, at least one composing element of the high-pressure turbine, the low-temperature, intermediate-pressure turbine and the low-pressure turbine is formed of a ferritic alloy steel, and a rotor and a casing of the high-temperature, intermediate-pressure turbine are formed of, on percentage by weight basis, one alloy selected from a group consisting of 1) to 4): 1) an alloy consisting of Ni: 50.0 to 55.0, Cr: 17.0 to 21.0, a total of Nb or Nb and Ta: 4.75 to 5.5, Mo: 2.8 to 3.3, Ti: 0.65 to 1.15, Al: 0.2 to 0.8, Co: 1.0 or less, C: 0.08 or less, Mn: 0.35 or less, Si: 0.35 or less, B: 0.006 or less and the balance of Fe and unavoidable impurities; 2) an alloy consisting of C: 0.25 or less, Si: 1.0 or less, Mn: 1.0 or less, Cr: 19.0 to 24.0, Co: 15.0 or less, Mo: 8.0 to 10.0, a total of Nb and Ta: 4.15 or less, Al: 1.5 or less, Ti: 0.6 or less, Fe: 20.0 or less, W: 1.0 or less, B: 0.01 or less and the balance of Ni and unavoidable impurities; 3) an alloy consisting of C: 0.2 or less, Si: 1.0 or less, Mn: 1.0 or less, Cr: 12.0 to 21.0, Co: 22.0 or less, Mo: 10.5 or less, a total of Nb and Ta: 2.8 or less, Al: 0.4 to 6.5, Ti: 0.5 to 3.25, Fe: 9.0 or less, B: 0.02 or less, Zr: 4.0 or less and the balance of Ni and unavoidable impurities; and 4) an alloy consisting of C: 0.45 or less, Si: 1.0 or less, Mn: 2.0 or less, Cr: 19.0 to 25.0, Ni: 18.0 to 45.0, Mo: 2.0 or less, Nb: 0.1 to 0.4, W: 8.0 or less, Ti: 0.6 or less, Al: 0.6 or less, B: 0.01 or less, N: 0.25 or less and the balance of Fe and unavoidable impurities; and at least a first stage turbine blade of turbine blades constructed of plural stages of the high-temperature, intermediate-pressure turbine is formed of, on percentage by weight basis, one alloy selected from a group consisting of 5) to 9): 5) an alloy consisting of Ni: 50.0 to 55.0, Cr: 17.0 to 21.0, a total of Nb or Nb and Ta: 4.75 to 5.5, Mo: 2.8 to 3.3, Ti: 0.65 to 1.15, Al: 0.2 to 0.8, Co: 1.0 or less, C: 0.08 or less, Mn: 0.35 or less, Si: 0.35 or less, B: 0.006 or less and the balance of Fe and unavoidable impurities; 6) an alloy consisting of C: 0.25 or less, Si: 1.0 or less, Mn: 1.0 or less, Cr: 19.0 to 24.0, Co: 15.0 or less, Mo: 8.0 to 10.0, a total of Nb and Ta: 4.15 or less, Al: 1.5 or less, Ti: 0.6 or less, Fe: 20.0 or less, W: 1.0 or less, B: 0.01 or less and the balance of Ni and unavoidable impurities; 7) an alloy consisting of C: 0.2 or less, Si: 1.0 or less, Mn: 1.0 or less, Cr: 12.0 to 21.0, Co: 22.0 or less, Mo: 10.5 or less, a total of Nb and Ta: 2.8 or less, Al: 0.4 to 6.5, Ti: 0.5 to 3.25, Fe: 9.0 or less, B: 0.02 or less, Zr: 4.0 or less and the balance of Ni and unavoidable impurities; 8) an alloy consisting of C: 0.45 or less, Si: 1.0 or less, Mn: 2.0 or less, Cr: 19.0 to 25.0, Ni: 18.0 to 45.0, Mo: 2.0 or less, Nb: 0.1 to 0.4, W: 8.0 or less, Ti: 0.6 or less, Al: 0.6 or less, B: 0.01 or less, N: 0.25 or less and the balance of Fe and unavoidable impurities; and 9) an alloy consisting of C: 0.1 or less, Si: 1.5 or less, Mn: 1.0 or less, Cr: 11.0 to 20.0, a total of Ni and Co: 40.0 to 60.0, Mo: 2.5 to 7.0, Al: 0.35 or less, Ti: 2.3 to 3.1, Zr: 0.1 or less, B: 0.001 to 0.02 and the balance of Fe and unavoidable impurities.