Type 439 (UNS S43035)
Type 439 is an 18% chromium, titanium stabilized ferritic stainless steel with corrosion resistance similar to that of 304/304L stainless steel. This grade may be used in the annealed, cold formed or as-welded condition in applications where other stainless steels such as Type 304/304L and Type 430 are used. Type 439 has good weldability due to titanium stabilization and has excellent resistance to stress corrosion cracking. Type 439 outperforms Type 409 in both oxidation and corrosion resistance and typical applications include tubular manifolds and exhaust system components.