Liquid Nitriding (LN) is a common term for a diffusion process that is actually liquid nitrocarburizing; a thermo-chemical reaction whereby nitrogen, primarily, and some carbon are diffused into the surface of iron-based materials. The nitrogen combines with the iron to form an iron-nitride compound layer that provides improved surface properties; e.g. resistance to wear, friction, corrosion, and fatigue.
Salt bath nitriding / liquid nitriding advantages include active case hardening process (compound zone), additional lubricity, improved corrosion resistance, as well as improved aesthetics. Dimensional stability of processed parts does not change and core properties are uncompromised.
Salt bath nitriding / liquid nitriding can be performed on through hardened steel. This yields the benefits of through hardening in the addition to a harder surface. This can be up to 75Rc, depending on the material.