Carbonitriding of four types of steels, namely, low carbon steel (LCS), medium carbon steel (MCS), low alloy steel (LAS) and high alloy steel (HAS) was achieved using cyanide salt bath heat treatment process. The steels, after preheating, were heated in a diesel fired salt bath heat treatment furnace and then quickly quenched in different media including air, oil and brine. The heat treatment p...