PRODUCTION OF HIGH-AND LOW-PRESSURE INTEGRAL TYPE TURBINE ROTOR

摘要

PURPOSE: To improve the toughness of a high- and low-pressure integral type turbine rotor. CONSTITUTION: A rotor blank consisting of a Cr-Mo-V based iron allay is subjected to a normalizing treatment at 1000 to 1150 deg.C and is held at 650 to 730 deg.C during the course of the cooling thereof to effect pearlite transformation. Further, the rotor blank is subjected to >=1 times of the normalizing treatments at 920 to 950 deg.C and, thereafter, the parts corresponding to the high-pressure part or middle-pressure part are quench-hardened by heating to 940 to 1020 deg.C and the parts corresponding to the low-pressure part to 850 to 940 deg.C; thereafter, the rotor blank is subjected to >=1 times of tempering at 550 to 700 deg.C. As a result, good high-temp. creep characteristics are obtd. in the parts corresponding to the high- and middle-pressure parts and the toughness of the low-pressure part is greatly improved.