Kinetics of the Low Temperature Hot Corrosion of Co‐Cr‐Al Alloys

Hot corrosion rates have been measured on many Co‐Cr, Co‐Al, and Co‐Cr‐Al alloys coated with 2.5 mg/cm 2 of and exposed in at 750°C. The hot corrosion resistance of the binary alloys increases with the chromium and aluminum content of the alloys. However, the additions of aluminum to Co‐Cr and of chromium to Co‐Al alloys have deleterious effects. These results can be explained on the basis of a mechanism similar to one previously proposed in the literature (1, 2). Additional experiments have been conducted as a function of temperature and the content of oxygen to extend the proposed mechanism.