Surface engineering since 1992
A controlled surface layer for components exposed to adhesive wear, scuffing and sliding contact. Patt selects compound-layer structure and supporting diffusion depth together, around the steel, mating surface and load.
During nitriding, iron nitrides can form a compound layer above the diffusion zone. This layer is often called the white layer because of its appearance in an etched metallographic section. Gamma-prime (γ′), epsilon (ε) and mixed-phase structures have different characteristics that must be matched to the application.
The target is a useful layer architecture, not simply maximum thickness. Phase balance, thickness, porosity, surface finish and diffusion support all matter. A thin layer or a compound-layer-free diffusion treatment may suit parts where edge integrity, impact loading or subsequent finishing governs the specification.
| Material family | Application and process focus |
|---|---|
| Carbon and low-alloy steels | Sliding surfaces, shafts and sleeves; review core strength and required diffusion support. |
| Nitriding steels and selected tool steels | Loaded wear parts and tooling; coordinate alloy response, layer thickness and finishing. |
| Stainless steels | When corrosion retention is required, review the low-temperature stainless route separately from an iron-nitride compound-layer specification. |
Identify the mating material, contact pressure, lubrication, sliding motion, edge loading and previous failure pattern. These details guide the surface specification. Patt combines nitriding development with machining and inspection to coordinate masking, functional surfaces and finishing requirements.
Provide the alloy, core hardness, prior heat treatment, drawing and service conditions. Specify compound-layer thickness limits, diffusion depth, final surface finish and masked areas. Agree on cross-sectional inspection and any phase verification needed. Inconel and titanium treatments are also available through Patt’s alloy-specific review; iron-nitride layer terminology does not apply to them.
Compare nitriding treatments
Diffusion depth, stainless surface hardening and compound-layer design address different contact demands.
A supporting diffusion case for abrasive wear, sliding contact and fatigue resistance. Suited to H13, H11, nitriding steels and suitable quenched-and-tempered alloy steels. Case depth and compound-layer thickness are selected around the core hardness and loading.
ExploreSurface hardening for wear and galling control while preserving the required stainless corrosion behaviour. S-phase processing applies to austenitic grades such as 304 and 316L; martensitic and PH stainless grades use alloy-specific expanded-martensite routes, including Patt steels.
ExploreSend the alloy designation, previous heat treatment and core hardness, drawing or dimensions, quantity, areas to treat or mask, and operating conditions. Include the wear or failure problem, target case depth and surface hardness if specified, final tolerances and required delivery date.