Oxidation and hot-corrosion resistant high aluminum austenitic stainless steel

A new type of austenitic stainless steel has been developed containing 5 pct Al and forming a protective Al2O3 film. This steel is free from oxide film spoiling and exhibits a greater oxidation and hot corrosion resistance than any other conventional austenitic stainless steels. By adjusting the Ni content and the addition of Ce and/or Ti, its manufacturability, workability and weldability have been improved to the point that this steel is now equal in quality to commercially available stainless steels. Formation of Al2O3 film requires the removal of the internal oxidation zone brought about by hotworking and welding, prior to being subjected to high temperatures. Abnormal oxidation also takes place in this steel, but has a less effect than in conventional ferritic CrAl steels.