SIMULATION OF NITRIDING PROCESSES

In the past, most scientific work to predict nitriding/nitrocarburizing results focused on applying thermodynamics on pure iron and binary or ternary alloys with nitride-forming elements and/or carbon.

While solubility and interface in pure iron can be derived from iron-nitrogen and iron-nitrogen-carbon phase diagrams, the presence of nitride- and carbide-forming elements in real steels has a greater influence on the growth kinetics of the diffusion and compound layers. Additionally, when treating steel parts, the pre-nitriding condition of the material has to be considered.

In this paper, we present a new simulation that calculates thermodynamic and kinetic effects based on material composition and pre-nitride condition. The model simulates recipes, up to three stages, with varying temperatures and nitriding potentials, and also taking into account nucleation time. The simulation gives compound layer thickness, precipitation and total diffusion depth, and calculates surface hardness, core hardness and effective case depth (+ 50 HV).