Sulfidation- and Oxidation-Resistant Ferritic Stainless Steel Containing Aluminum

摘要

Recent developments in energy conversion, mining and minerals processing, pollution control, and chemical equipment have placed increased demands on heat-resistant alloys. Higher corrosion rates from oxidation, hot corrosion, and sulfidation have increased consumption of materials that contain critical and strategic minerals and in many cases have limited productivity. The substitute materials are based on Fe-Cr-Ni-Al compositions. Aluminum additions to Fe-Cr-Ni alloys significantly improve high-temperature corrosion resistance, particularly sulfidation resistance. In the alloy, devised by Bureau researchers, aluminum additions are held in the form of a second-phase precipitate, beta-NiAl. Minor additions of Ti, Mn, and Si improve workability. Mechanical properties approach those of type 310 stainless steel.