THERMOOMECHANICAL TREATMENT METHOD FOR AUSTENITIC STAINLESS STEEL PIPE TO GIVE HOT STEAM OXIDATION RESISTANCE

摘要

PURPOSE:To enhance the hot steam oxidation resistance of an austenitic stainless steel pipe by specifying the cold working ratio of the pipe and the heating condition in soln. heat treatment and organically combining the cold working and heat treatment. CONSTITUTION:An austenitic stainless steel pipe is subjected to cold working such as grinding, metal brushing or shot peening at a working ratio above 20%. The cold worked pipe is then heated to 1000 - 1200 deg.C at a heating rate below 2.9 deg.C/set to carry out soln. heat treatment. The resulting pipe does not undergo stress corrosion cracking and deterioration in creep rupture strength and does not form scale even if exposed to hot steam over a long time. Thus, the pipe has enhanced hot steam oxidation resistance.