Fig. 1

Gas nitriding thermochemical treatment. (a) Sample inside vacuum chamber of SF40 before gas nitriding with CSE; (b) Thermal cycle of S11 sample (900 °C, 15 min) in EF; (c) Temperature, radiation, and shutter aperture during gas nitriding of S21 sample in SF (900 °C, 15 min); (d) simplified diagram of the overall experimental procedure.