ABSTRACT
Resistance heating alloys are metal alloys that can be used for electrical heating purposes above 600°C in air. When an oxide layer has formed on the wire surface at a high temperature and the wire is subsequently cooling down, the metallic wire is exposed to tension and the oxide is compressed. The life comparison of different resistance heating alloys is often carried out by tests according to the ASTM standards. The life of a wire can be expected to increase with the amount of available Al and Cr counted per wire surface unit, which is proportional to the ratio between the cross section and the circumference of the resistance heating wire. Resistance heating wire is made by repeated drawing and annealing, and annealing is normally the last operation, so that the wire is usually delivered in a soft annealed state. A distinction must be made between corrosion in wet and in hot states.
