Nitridiaatio
Nitridiaatio is a Finnish term referring to the process of nitriding, a thermochemical surface hardening treatment for steels. This process involves diffusing nitrogen atoms into the surface layer of a steel component. The nitrogen atoms react with alloying elements present in the steel, such as chromium, aluminum, vanadium, and molybdenum, to form very hard, fine nitride precipitates. These precipitates are dispersed within a diffusion zone, which is a nitrogen-rich layer. The primary benefit of nitridiaatio is the creation of a hard, wear-resistant surface while maintaining a tough core. This is achieved without significant distortion, making it ideal for precision components. The process typically occurs at temperatures below the lower critical transformation temperature of the steel, usually between 500 and 575 degrees Celsius. The duration of the nitridiaatio process can vary depending on the desired case depth and the specific steel composition. Different methods can be employed for nitridiaatio, including gas nitriding, salt bath nitriding, and plasma nitriding. Each method offers distinct advantages and disadvantages concerning control, cost, and environmental impact. Applications for nitrided components are widespread and include gears, crankshafts, dies, and cutting tools where enhanced surface hardness and fatigue strength are crucial.