The ferritic stainless steel null mass which is superior in resistance high-temperature oxidation Characteristic and scale

摘要

PROBLEM TO BE SOLVED: To provide an inexpensive steel usable for a pipeline member for high temperature exhaust gas of 700 to 950 deg.C. SOLUTION: The steel is constituted of a ferritic stainless steel which has a composition consisting of, by mass, =0.03% C, 0.80-1.20% Si, 0.60-1.50% Mn, 11.0-15.5% Cr, 0.20-0.80% Nb, =0.1% Ti, 0.02-0.30% Cu, =0.03 N, =0.05 Al, 0.012% O, and the balance Fe with inevitable impurities and simultaneously satisfying the relations of 0.7=Mn/Si=1.5, 1.4=Nb+1.2Si=2.0, and 1,221.6(C+ N)-55.1Si+65.7Mn-8.7Cr-99.5Ti40.4Nb+1.1Cu+54=0. In this steel, the amount of increase in oxidation and the amount of peeling of scale after continuous heating under the air atmosphere at 900 deg.C for 100 hr are regulated to =0.02 kg/m2 and =0.01 kg/m2 , respectively, and also the amount of increase in oxidation and the amount of peeling of scale after continuos heating similarly at 1,000 deg.C for 100 hr are made to =0.4 kg/m2 and =0.02 kg/m, respectively.