Production mannered null mass of high purity high Cr ferritic heat resisting steel and high purity high

摘要

PROBLEM TO BE SOLVED: To provide a turbine member superior in high temperature characteristics to the conventional one and to improve the efficiency of a power system.;SOLUTION: A heat resisting steel ingot, having a composition containing 0.06-0.11% C, 9.5-10.5% Cr, 0-1.0% Mo, 0.10-0.25% V, 0.03-0.08% Nb, 3.0-5.0% W, 2.5-6.0% Co, 0.002-0.015% B and 0.015-0.025% N, is refined by an electroslag remelting process, hot forged, quenched at 1060-1120°C, tempered at 500-620°C (or tempered at 500-580°C and held at 620-680°C), and further tempered at 690-740°C. A structure where a Laves phase is finely and uniformly dispersed through a tempered martensitic single phase can be obtained, and high temperature characteristics can be remarkably improved. By using this material for the turbine member, a power system with higher efficiency can be constructed.;COPYRIGHT: (C)2001,JPO