Strength at elevated temperature and the FeCrAl ferritic stainless steel null which is superior in resistance high-temperature oxidation Characteristic and diffused-junction

摘要

PROBLEM TO BE SOLVED: To obtain an Fe-Cr-Al ferritic stainless steel excellent in high temp. strength, high temp. oxidation-resistance and diffusion joinability by specifying the compsn. composed of C, Si, Mn, P, S, Cr, N, Al, Mo, Nb, rare earth metals and Fe in a steel, annealing the steel in a reducing atmosphere and thereafter subjecting it to cold rolling to regulate its roughness into specified one. ;SOLUTION: A stainless steel having a compsn. contg., by weight, ≤0.03% C, ≤1% Si, ≤1% Mn, ≤0.04% P, ≤0.003% S, 15 to 25% Cr, ≤0.03% N, 3.5 to 6.0% Al, 0.1 to 2.0% Mo, 0.01 to 0.3% Nb, 0.01 to 0.2% rare earth metals, and the balance substantial Fe, in which Al and Mo also lie within the region obtained by connecting (a), (b), (c) and (d) in two-dimensional co-ordinates, and the relationships of 28014.6Al+24.2Mo+481Nb%≥100 and Al+10Nb≤7.0 are satisfied is annealed in an atmosphere of ≥90 vol.% reducing gas and is thereafter subjected to cold rolling. The surface 10 point average roughness Rz in a direction orthogonal to the rolling direction of the obtd. cold rolled steel sheet is regulated to ≤1.0 μm.;COPYRIGHT: (C)1998,JPO