Steam turbine rotor and steam turbine using the same

Abstract

To provide a steam turbine rotor and a steam turbine which are highly reliable. The steam turbine rotor is characterized in that a forged material B having a hollow structure is joined to a forged material A of a Ni group super-alloy by welding, and weld back waves on an inner surface are removed, and the inner surface is smoothed, and a forging material C and a forging material B are joined to each other with a bolt.

1 . A steam turbine rotor for joining a forged material B having a hollow structure to a forged material A of a Ni group super-alloy by welding, removing weld back waves on an inner surface, smoothing the inner surface, and joining a forging material C and the forging material B with a bolt. 
     
     
         2 . The steam turbine rotor according to  claim 1 , wherein a temperature at which a welded portion is exposed when in use is 500° C. or higher and a temperature of a bolt joint portion is lower than 500° C. 
     
     
         3 . The steam turbine rotor according to  claim 2 , wherein the forging material B is a Ni group super-alloy and the forging material C is CrMo V steel. 
     
     
         4 . The steam turbine rotor according to  claim 2 , wherein the forging material B is ferrite steel and the forging material C is CrMo V steel. 
     
     
         5 . The steam turbine rotor according to  claim 3 , wherein a shaft portion is not subject to wear resistance weld buildup and wear resistance spray coating. 
     
     
         6 . A steam turbine using a steam turbine rotor described in  claim 1 .