Diamond turning on nitriding diffusion layer of pure iron

Abstract The nitriding diffusion layer has been considered wearing excessively during diamond turning due to its low nitrogen content in previous research. In this study, by increasing the gas flow rate during the cooling process, an extra needle-precipitates free phase sublayer with a thickness of 25 μm was formed beneath the compound layer, along with the traditional diffusion layer. The microstructure was analyzed and diamond turning test was carried out on each sublayer. After diamond turning all sublayers, no significant wear was observed on the diamond tool. The α-Fe(N) phase with supersaturated nitrogen atoms was found that it can inhibit the wear of the diamond tool. The needle-free precipitates phase sublayer had the lowest surface roughness value after diamond cutting, which was 6.10 nm.