Ferritic Stainless Steels for High Temperature Applications in Oxidizing Environments

Ferritic stainless steel containing more than 7 wt. % of Al represents an interesting material for the production of components working at high temperature. To meet industrial needs of increased operating temperatures, many studies have been carried out to design FeCrAl(RE) alloys that are suitable for applications where the components have to work in oxidative environments for extended periods of operation, often at very high temperatures (>1000 °C) under cyclic operating conditions. Although a very good protectiveness against oxidation can be achieved for Al concentrations higher than 7 wt.%, mechanical properties of FeCrAl alloys are known to be poor at high temperature. High temperature strength and creep resistance can be improved by reducing grain boundary areas and by precipitating stable particles in the bulk alloy: this practice prevents grain boundary slip and dislocation movement. This paper reviews the patented progresses in the field of the production of FeCrAl alloys for high temperature applications such as heating elements and substrate of catalytic converters. © 2009 Bentham Science Publishers Ltd.