"Nikrothal® PM 58 and Kanthal® APMT™ – alumina forming high temperature steels offering new opportunities in heat treatment"

Energy efficient heat processing will be crucial in meeting the challenges of a growing global population and combating climate change. This often sets demands on higher operating temperatures and/or reduced cooling. A limiting factor in this respect is often material issues i.e materials that can withstand extreme temperatures and corrosive atmospheres.

In this paper, two novel, alumina forming steels, Kanthal^® APMT™ and Nikrothal^® PM 58, are presented. In both cases, the steels base their corrosion resistance on the formation of an adherent alumina layer. This along with a high creep resistance, due to a dispersion strengthened microstructure from the powder metallurgical processing route. This unique combination of properties enables application temperatures ranging from 1470 °F to 2282 °F and new possibilities to design high temperature components, one example is furnace rollers with reduced or removed water-cooling. Mechanical and corrosion properties for the two steels at high temperatures will be presented and compared with other commercial materials.