METHOD FOR MANUFACTURING HIGH-CHROMIUM FERRITIC/MARTENSITIC HEAT-RESISTANT ALLOY

摘要

PROBLEM TO BE SOLVED: To provide such a method for heat-treating a high-chromium ferritic/martensitic heat-resistant alloy as to impart it superior creep rupture strength while imparting it similar impact properties to those obtainable in a conventional heat treatment method. SOLUTION: The method for manufacturing the high-chromium ferritic/martensitic heat-resistant alloy comprises the processes of melting, hot working and heat treatment. The heat treatment process comprises the steps of: normalizing the alloy at 1,030 to 1,100°C; tempering it first at 620 to 720°C; and tempering it secondly at 730 to 780°C. The high-chromium ferritic/martensitic heat-resistant alloy manufactured through the manufacturing method has the superior impact properties and superior creep rupture strength, because of having a stable structure which contains finely dispersed chromium carbonitrides with sizes of several tens of nanometers, and contains no martensite. COPYRIGHT: (C)2005,JPO&NCIPI