Nitriding improves the endurance of wear parts and so is widely used for components such as gears, cam shafts and followers, valve parts, dies, extruder screws and injectors. The depth of the nitrided case can be finely controlled as the nitrogen bonds with alloys in the base metal to form compounds of chromium, molybdenum or aluminium.
Salt bath is the traditional treatment, available from fewer processors these days. Ideal for use on steel and its alloys, it gives good process times and is straightforward. Various salt compounds may be used to suit different substrates and achieve specific hardening targets.
Gas nitriding is most suited to large batch sizes and provides very consistent results because temperature, gas concentration and time are closely controlled in computerised furnaces. This is a cleaner process than salt bath so that components do not need any post treatment cleaning. However, care needs to be taken in component preparation, since surface contamination can adversely affect the final result.
Plasma nitriding, using an ionised donor gas, usually nitrogen, has the major advantage of being a comparatively cool process. As a result the dimensions and characteristics of the base material are not adversely affected. There are no residues and the process is can followed by PVD coating to impart more beneficial properties.
Being able to offer all processes, we can give impartial advice taking into account technical factors such as the application of the component, material from which it is made, and required process time as well as comparative cost.