Steam turbine rotor, steam turbine using the steam turbine rotor, and thermal power plant using the steam turbine

摘要

It is an objective of the invention to provide a steam turbine rotor of which a rotor shaft is made of a low-cost heat resistant ferritic steel and that can withstand high main steam temperatures of about 650°C. There is provided a steam turbine rotor comprising: a rotor shaft made of a heat resistant ferritic steel such as a 12-Cr steel; and a rotor blade made of a Ti-Al alloy, wherein the Ti-Al alloy includes: from 38 to 45 atomic % of Al; from 0.5 to 2 atomic % of V; from 2 to 6 atomic % of Cr and/or Mo; and the balance being Ti and incidental impurities.