TURBINE ROTOR MADE OF BUILD-UP REINFORCING TYPE 12 CR STEEL HAVING EXCELLENT FATIGUE STRENGTH

摘要

PROBLEM TO BE SOLVED: To provide a turbine rotor made of a Cr steel of a build-up welding type having excellent seizure resistance and fatigue strength characteristics in combination. ;SOLUTION: The contact surfaces with bearings of the turbine rotor made of 12% Cr steel are reinforced by multilayered build-up welding of the Cr-contg. steel and the differences in the Cr contents between the rotor base material and the root pass build-up weld metal and between the respective build-up weld metal layers in build-up weld zones are all ≤4.0wt.% or the differences in the Cr contents between the rotor base material and the root pass build-up weld metal and between the respective build-up weld metal layers in the build-up weld zones are all ≤6.0wt.%. At least one kind selected from the group consisting of Nb, V, W, Mo and Ti are incorporated into the build-up weld metals on the side where the Cr content is lower within a range satisfying the relation of the following formula: 0.15wt.%≤Nb+(1.3)V+(1.5)W+(1/3)Ti+(1/5)Mo≤2.0wt.%.;COPYRIGHT: (C)1997,JPO