ATI - Model 409 Cb - Ferritic Stainless Steels Brochure

ATI 409HP (UNS S40900) ferritic stainless steel was introduced by ATI in 1961 to provide improved oxidation and corrosion resistance for automotive exhaust systems in comparison to carbon steel. The alloy was designated "MF-I", indicating its end use: automotive mufflers. The good fabricability of this alloy, combined with its basic corrosion resistance and economy have significantly broadened the utility of ATI 409HP™ stainless.