FRICTION AND WEAR BEHAVIOR OF CHROMIUM CARBIDE COATINGS

Chromium carbides, tungsten carbide and chromium oxide have been tested and evaluated as coatings to protect high temperature gas-cooled reactor (HTGR) steam generator and other HTGR components from adhesion, galling associated with sliding wear or from fretting. Several types of chromium carbide coatings including Cr//3C//2, Cr//7C//3 and Cr//2//3C//6 were tested for wear resistance and resistance to long-term spalling. Tungsten carbide and chromium oxide coatings were tested in sliding wear tests. Cr//2//3C//6-NiCr coatings showed the best performance (from 400 to 816 degree C) whether they were applied by detonation gun or plasma gun spraying methods.