To lengthen a final stage moving blade of a steam turbine, and generate power with a high efficiency by forming a length of a blade part to a specified value of more, subjecting inclination of a width direction of the blade part to be in nearly parallel with an axial direction of a rotary shaft in the vicinity of an implant part, inclining a tip end of the blade part by a specified value from an axial direction, and making the blade part of martensite steel.
A width direction of blade part 51 of a long blade of 40 inches or more is gradually inclined by 65 to 85 degrees from an axial direction at a tip end of the blade, and a blade implant part 52 is nearly in parallel with the axial direction of an axis. The long blade material is made of martensite steel including Co: 15 to 0.25%, Si: 0.25% or less, Mn: 0.90% or less, Cr: 8.0 to 13.0%, Ni: 2 to 3.5%, Mo: 1.5 to 3.5%, V: 0.05 to 0.35%, total quantity of one kind or two kinds of Nb and Ta is 0.02 to 0.20%, and N: 0.04 to 0.15%, in a weight ratio. The long blade has to be improved in high cycle fatigue strength simultaneously in tension strength. Accordingly, a metal texture of the blade material is made of full temper martensite texture.
NAKAMURA SHIGEYOSHI
ONODA TAKESHI
SHIGA MASAO
HIRAGA MAKOTO
