| 摘要 |
PROBLEM TO BE SOLVED: To produce a low alloy steel having toughness equal to or above that of the conventional one, excellent in high temperature strength and particularly free from creep toughness in a CrMoV heat resistant alloy used for a turbine rotor, to provide a method for producing the same and to produce a turbine rotor using the same. SOLUTION: In a CrMoV heat resistant alloy, the contents of trace impurities of phosphorous, sulfur, copper, aluminum, arsenic, tin and antimony are reduced to specified levels or less. Moreover, trace impurities such as cobalt, niobium, tantalum, nitrogen, boron are added to increse its flat creep strength. Moreover, as for the method for producing the same, quenching is performed from a high temperature of 1,000 deg.C or more to suppress the precipitation of a pro-eutectoid ferritic phase.
|
