Nitrocarburointi

Nitrocarburiing is a thermochemical surface hardening process used to improve the wear resistance and fatigue strength of steel components. It involves diffusing both nitrogen and carbon into the surface layer of the metal simultaneously. This process is typically carried out at elevated temperatures, usually between 500°C and 570°C, in a controlled atmosphere. The atmosphere is rich in nitrogen and carbon-containing gases, such as ammonia and hydrocarbon derivatives.

The diffusion of nitrogen and carbon creates a compound layer on the surface, which is very hard and brittle. Beneath this compound layer, a diffusion zone is formed, where nitrogen is dissolved in the steel matrix, leading to a significant increase in hardness and fatigue strength. This diffusion zone is less brittle than the compound layer and provides a tough core.

Nitrocarburiing is often performed in gas furnaces, salt baths, or plasma environments. The specific parameters, such as temperature, time, and gas composition, are carefully controlled to achieve the desired case depth and surface hardness. The process is suitable for a wide range of steel grades, including low-carbon steels, medium-carbon steels, and alloy steels.

Benefits of nitrocarburiing include enhanced wear resistance against abrasion and adhesion, improved fatigue life, and increased corrosion resistance. The process can also impart a desirable black finish to the component. It is commonly applied to automotive parts, gears, shafts, tools, and other components subjected to significant wear and stress. Unlike nitriding, nitrocarburiing introduces both nitrogen and carbon, resulting in a different phase structure and properties.