Patent ID: 7553555

Claim:
A vapour turbine operating with geothermal vapours containing corrosive agents including chlorides and/or sulfides wherein said turbine comprises a series of stator blades made of a nickel-chromium-molybdenum (NCM) alloy containing a quantity of nickel ranging from 54% to 58% by weight of said NCM alloy, a quantity of chromium ranging from 21% to 23% by weight of said NCM alloy, and a quantity of molybdenum ranging from 12% to 14.5% by weight of said NCM alloy; wherein said turbine further comprises a series of rotor blades made of a nickel-chromium-molybdenum-niobium (NCNM) alloy, and wherein said NCMN alloy comprises a quantity of nickel ranging from 55% to 59% by weight of said NCMN alloy, a quantity of chromium ranging from 19% to 22.5% by weight of said NCMN alloy, a quantity of molybdenum ranging from 7.0% to 9.5% by weight of said NCMN alloy, and a quantity of niobium ranging from 2.75% to 4% by weight of said NCMN alloy.