Ferritic stainless steel sheet, method for the production thereof, and use of the same, especially in exhaust lines

Abstract

A ferritic stainless steel sheet of a composition, expressed in weight percentages: trace amounts≦C≦0.03%; 0.2%≦Mn≦1%; 0.2%≦Si≦1%; trace amounts≦S≦0.01%; trace amounts≦P≦0.04%; 15%≦Cr≦22%; trace amounts≦Ni≦0.5%; trace amounts≦Mo≦2%; trace amounts≦Cu≦0.5%; 0.160%≦Ti≦1%; 0.02%≦Al≦1%; 0.2%≦Nb≦1%; trace amounts≦V≦0.2%; 0.009%≦N≦0.03%; trace amounts≦Co≦0.2%; trace amounts≦Sn≦0.05%; rare earths (REE)≦0.1%; trace amounts≦Zr≦0.01%; the remainder of the composition consisting of iron and of inevitable impurities resulting from the elaboration; the Al and rare earth (REE) contents satisfying the relationship: Al+30×REE≧0.15%; the Nb, C, N and Ti contents in % satisfy the relationship: 1/[Nb+(7/4)×Ti−7×(C+N)]≦3; said metal sheet having an entirely recrystallized structure and an average ferritic grain size comprised between 25 and 65 μm. A method for manufacturing such a ferritic stainless steel sheet, and its use for manufacturing parts involving shaping and welding and intended to be subject to a periodic temperature of use comprised between 150° C. and 700° C. and to a projection of a mixture of water, urea and ammonia.