Liquid carburizing is a method of case-hardening or carburizing steel in molten
baths. The baths are mixtures of cyanides, chlorides, and carbonates. The case that is
produced is comparable with one resulting from pack or gas carburizing. The salts
produce carbon and nitrogen that penetrate the surface.
The carburizing action depends upon sodium cyanide or barium cyanide, which
supplies the carbon and some nitrogen. Non-cyanide carburizing applications are
available. They produce excellent results.