Heat-resisting steel, heat treatment method for heat-resisting steel and high-temperature steam turbine rotor

摘要

A heat-resisting steel consisting of, in percentage by weight, 0.25 to 0.35 of C, 0.15 or less of Si, 0.2 to 0.8 of Mn, 0.3 to 0.6 of Ni, 1.6 to 1.9 of Cr, 0.26 to 0.35 of V, 0.6 to 0.9 of Mo, 0.9 to 1.4 of W, less than 0.01 of Ti, 0.001 to 0.007 of N, 1.3 to 1.4 of a total of Mo and W/2 and the balance of Fe and inevitable impurities, wherein the heat-resisting steel consists of a bainite single phase structure securing 3.5 or more of a total amount of precipitates as 1.0 or more of Fe, 0.8 to 0.9 of Cr, 0.4 to 0.5 of Mo, 0.3 to 0.5 of W and 0.2 or more of V in percentage by weight are moved into the precipitates after a tempering heat treatment.