Nitrocarburiing

Nitrocarburizing is a thermochemical surface hardening process used to improve the wear resistance, fatigue strength, and corrosion resistance of steel components. It involves diffusing nitrogen and carbon atoms into the surface layer of the metal at elevated temperatures, typically between 500 and 600 degrees Celsius. The process is carried out in a controlled atmosphere, which can be gaseous, liquid (salt bath), or plasma.

The diffusion of nitrogen and carbon creates a compound layer on the surface, which is typically a hard, brittle layer composed of iron nitrides and carbonitrides. Beneath this compound layer is a diffusion zone, where nitrogen and carbon atoms have diffused into the steel's matrix, forming solid solutions and precipitating nitrides and carbides, which contribute to increased hardness and fatigue strength.

Nitrocarburizing is often considered a low-distortion hardening process, meaning it causes less warping of the part compared to traditional carburizing or hardening methods. This makes it suitable for treating finished or near-finished components. Various types of nitrocarburizing exist, including gas nitrocarburizing, salt bath nitrocarburizing, and plasma nitrocarburizing, each offering different advantages in terms of control, efficiency, and suitability for specific applications. The specific properties achieved depend on the base material, process temperature, time, and the composition of the treatment atmosphere. Applications range from automotive components like crankshafts and camshafts to tooling and industrial machinery parts.