Intergranular corrosion resistance, pipe formation properties and ferritic stainless steel excellent in high temperature strength

摘要

PURPOSE:To obtain a stainless steel constituting the passage of high temp. combustion gas and having satisfactory intergranular corrosion resistance, tube making property, and strength at high temp. CONSTITUTION:The steel is a ferritic stainless steel having a composition which consists of, by weight, =0.02% C, =1.0% Si, =2.0% Mn, =0.08% P, =0.01% S, =0.6% Ni, 11.0-20.0% Cr, 0.1(or 0.3)-1.0% Nb, =1.0% V, =0.05% Al, =0.03% N, =0.01% 0, and the balance Fe with inevitable impurities and where a relationship of 0.005=C+N=0.04% and a relationship that the value of I determined by equation I=Nb-7(C+N)+0.01(Cr-12) is maintained at =0.15 or =0.30, are held among the above components. Further, this ferritic stainless steel has superior intergranular corrosion resistance, tube making property, and strength at high temp.