Reactions that occur at the surface of the part during Plasma Nitriding

This content focuses on the reactions that occur on the metal surface during the initial stages of plasma nitriding. Before diffusion begins, ion bombardment cleans the surface through sputtering or reductive reactions with hydrogen. This preparation enables nitrogen atoms to interact with the surface iron, initially forming FeN. With continued plasma exposure, this compound breaks down and transforms into phases such as Fe₃N (ε) and Fe₄N (γ’), which make up the functional layer.

• Removes contaminants that hinder nitrogen-metal interaction

• Activates the surface to initiate chemical reactions

• FeN forms as a transitional phase and evolves into stable nitrides

• Fe₃N and Fe₄N contribute hardness, low friction and corrosion resistance

• Final layer quality depends directly on the initial surface condition

In this infographic: a technical look at the surface reactions that mark the beginning of compound layer formation.