Alloy 347 is a chromium nickel stainless steel that has been enhanced with the addition of columbium and tantalum. This modification provides excellent resistance to intergranular corrosion, a common issue in other austenitic stainless steels when exposed to temperatures ranging from 800°F to 1500°F. It offers a comparable level of general corrosion resistance to Type 302.Alloy 347 finds extensive use in highly corrosive enviro nments, such as aircraft exhaust stacks, manifolds, and ring collectors. It is particularly suitable for heavy welded assemblies that cannot undergo annealing after welding or are exposed to temperatures between 800°F and 1500°F.