The testing of nitride layers is described in detail in the following standards:
DIN50190-3: Hardness depth of heat-treated parts; determination of the effective depth of hardening after nitriding
DIN EN-ISO 6507-1: Metallic materials – Vickers hardness test – Part 1: Test method
DIN 30902: Heat treatment of ferrous materials – Light-microscopical determination of the depth and porosity of the compound layer of nitrided and nitro-carburised ferrous parts
If you requirepractical tips for testing your components, feel free to get in touch! For example, a spot test can be used as a quick way to approve your furnace batch.