HIGH-TI, HIGH-MN AUSTENITIC STAINLESS STEEL FOR COAL GASIFICATION

摘要

PURPOSE:To obtain a high-Ti, high-Mn austenitic stainless steel having superior corrosion resistance and strength at high temp. in a coal-gasification environment, by specifying a composition consisting of C, Si, Ni, Cr, Mn, Ti, and Fe. CONSTITUTION:The high-Ti, high-Mn austenitic stainless steel for coal gasification has a composition consisting of, by weight, =0.15% C, =1.0% Si, 6-20% Ni, 13-20% Cr, 2-30% Mn, 2-5% Ti, and the balance Fe and further containing, if necessary, 0.001-0.1% of one or more elements among rare earth elements and Ca. In the above steel, components are regulated so that relations in Cr+2.2Ti+1.5Si-Ni-30C-0.5Mn=10 so as to properly control the formation of a ferritic phase. When the above steel is used as material for an exhaust heat recovering apparatus in coal gasification, the temp. and pressure of generated steam can be increased and improvement in efficiency can be attained.