White Layer in Plasma Nitriding: What It Is and Why It Matters
- redesiht
- Jun 10
- 1 min read

White layer is the outermost layer, with a maximum thickness of 25 micrometers (0.025 microns), rich in iron nitrides (Fe₄N and Fe₃N). It is characterized by:
High surface hardness: Significantly higher than the core material.
Wear resistance: Excellent resistance to abrasive and adhesive wear, especially the latter.
Potential brittleness: It may be more brittle compared to the diffusion zone.
Beneath the White Layer, there's a layer up to 0.7 mm thick, known as the Diffusion Zone, characterized by the presence of nitrogen diffused into the metallic matrix.
Maintains the hardness of the base material with improved wear characteristics.
Hardness decreases gradually from the white layer to the core.
Fatigue resistance: Enhanced due to the compressive stresses induced by nitrogen.
📊 Download infographic: Unveiling the Compound Zone (White Layer)
📊 Related resource: Reactions that occur at the surface of the part during Plasma Nitriding
📊 Related resource: White Layer, asset or liability?
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