Lifetime extension of FeCrAlRE alloys in air: Potential roles of an enhanced Al-reservoir and surface pre-treatment

Abstract

Two novel approaches to extend the lifetimes of commercial FeCrAlRE alloys, such as Aluchrom YHf and Kanthal AF, for industrial usage have been developed by the CEC funded SMILER Project. These surface treatments either increased the available alloy Al reservoir by alloying, aluminising, or cladding/plating or preformed an α-Al2O3 protective scale by gas annealing. An extensive series of evaluation testing in laboratory air, extending to either 3000 h or chemical failure whichever was shorter, has been undertaken at temperatures between 800° and 1300°C on alloy coupons in the form of both 50 μm thick foil or 1 mm thick sheet. This has been augmented by selected further exposures of surface treated near real-life components (fibre mat heater burners and alloy supports for automobile emission control catalysts). The results of all these evaluation tests are fully detailed in this paper and have established both the viability of these procedures and their range of technological applicability.