Chromium nitride as silver gray chromium nitride is not only an excellent additive for steel-making alloy, but also suitable for diamond tools, thermal spraying, cemented carbide, powder metallurgy.
Chromium nitride is made by nitriding low-carbon ferrochromium in vacuum furnace at 1150 C to obtain coarse ferrochromium nitride, which is then treated with sulfuric acid to remove iron impurities. Chromium nitride is obtained by filtration, washing and drying. It can also be prepared by the reaction of ammonia with chromium halide.
Chromium nitride has higher surface hardness, lower friction coefficient and lower residual stress, which make it suitable for wear resistance and metal-metal friction occasions. Used as wear resistant coating. Adding to mechanical parts and dies can enhance their lubricity and wear resistance.