2002 Volume 88 Issue 3 Pages 163-167
Recently, gas turbine inlet temperature has been raised in order to improve thermal efficiency of power plant. The turbine inlet temperature of 1500°C has already been attained in the newly developed gas turbine. In case of the combined cycle power plant, optimization of compressor pressure ratio corresponding to the increase of turbine inlet temperature is required to improve the thermal efficiency. Development of higher creep strength material for disk, therefore, is needed to actualize higher thermal efficiency gas turbine. Alloy design based on 12% Cr steels indicated that the high purity 10Cr1.5Mo0.75NiVNbN steel is suitable to the compressor disks required to the advanced type gas turbine. A trial disk has successfully been manufactured with this steel from 800 mm dia. electroslag remelting (ESR) ingot. Several evaluation tests revealed good material properties which meet the requirements of advanced type gas turbine compressor disk, especially in toughness and creep rupture strength.
