Development of Welded Rotors for High-Temperature Steam Turbines

Steam turbine plants face strict market demand for high-temperature operation, streamlining, and shortened delivery times. The welded rotor enables streamlining through the use of material most appropriate for high to low-temperature parts. The use of materials will also enable a shift to larger capacity and shorter delivery times. The hetero-material welded rotor consisting of 2.25CrMoV, 9%Cr, and 3.5NiCrMoV steel was developed to meet these demands and verified at Takasago combined cycle plant. The plant has been conducting commercial and proving operations on the rotors. In this paper the authors introduce verification of work execution, strength, thermal stability, inspection for the welded rotor, and actual machine commercial operation.© 2005 ASME