Description : | Nitriding is a surface-hardening heat treatment that introduces nitrogen atoms into the surface of steel at a temperature range of 500 - 550oC. The purpose of nitriding is to increase the surface hardness of the steel and improve its wear and corrosion resistance properties. Various nitriding methods, e.g. gas nitriding, liquid nitriding, plasma nitriding, have been applied to various ferrous alloys to achieve superior surface hardness. Conventionally gas or liquid nitriding are used - both of which are toxic in nature.
In contrast to these processes, plasma nitriding is carried out in a vacuum chamber where high-voltage electrical energy is used to form glow discharge plasma of the background gas (nitrogen and hydrogen) mixture. Ions from the plasma bombard metal surface leading to temperature rise, cleaning of the surface and provides nitrogen species which diffuses in the metal surface. |