| 摘要 |
PROBLEM TO BE SOLVED: To provide a catalyst support alloy for exhaust system, used for exhaust systems of automobiles of various kinds, and its production. SOLUTION: A catalyst support alloy, so constituted that an alumina type film is formed on the surface of a steel material having 0.3 to 2 mm sheet thickness and also having a composition, in the region between the surface and a position at a depth of 10μm from the surface, consisting of 8-25% Cr, 1.5-20% Al, and the balance Fe with <=3%, in total, of elements other than the above elements, has excellent properties. The properties can be improved by incorporating Si into the alloy. The properties of this material can be improved to a greater extent by subjecting a cold rolled steel sheet, having a steel composition consisting of <=0.8% Si, 8-25% Cr, 0.5% Al, and the balance Fe with inevitable impurities and also having the above-mentioned sheet thickness, to recrystallization annealing, to plating with an Al bath, and further to heating treatment in an oxygen-containing atmosphere so that the length of time at >=600 deg.C amounts to >=3 hr. This material has excellent properties required of a catalyst support for a two wheeler and can be economically produced.
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