Combination of Gas Soft-Nitriding and Laser Transformation Hardening

Recently, attention has being given to combining currently used techniques to derive desirable properties that hitherto could not be obtained. Accordingly, the effect of combining of gas soft-nitriding and laser transformation hardening on S45C and SCM435, and specifically on wear resistance, was investigated. Results obtained are summarized as follows: 1) The nitride layer formed by gas soft-nitriding was considerably decomposed by laser beam irradiation. 2) X-ray diffraction on specimens subjected to the combination treatment comfirmed the small amount of ε and γ', together with retained γ and FeO. 3) It was observed that the combination-treated specimen had a fine nitrogen-containing martensite structure with a high hardness of Hv 820. 4) Wear resistance of the combination-treated specimens improved markedly, particularly in the range of stationary wear. This was considered to be due to the high hardness of the fine nitrogen-containing martensite.