Answer: The white layer formation is a function of:
- Process gas ratios
- Processed steel chemistry
If the process-gas chemistry is changed (as can be quite easily with plasma nitriding) then the surface – compound layer – can also be changed. Conventional gas nitriding relies on the Floe process – two-stage nitriding – to reduce the thickness of the compound layer. This involves temperature and gas dissociation changes. Whereas with plasma nitriding, it is simply a change in gas ratios in relation to the steel being treated.