Improving the efficiency of surface-thermal hardening of machine parts in conditions of combination of processing technologies, integrated on a single machine tool base

OBRABOTKAMETALLOV Vol. 23 No. 3 2021 technology Fig. 13. Experimental results for parts made of U8 steel: a – optical microscopy; b – the simulation results of structural-phase transformations – distribution of the volume fraction of the martensite structure; c – the distribution of tangential residual stresses (simulation results); d – the distribution of microhardness and residual stresses in the surface layer: 1 – a calculated plot of the tangential residual stresses; 2 – a plot of residual stresses obtained experimentally (by mechanical destructive method); – residual stresses obtained by X-ray determination a b c d Fig. 14. Experimental results for parts made of 45 steel: a – optical microscopy; б – the distribution of microhardness and residual stresses in the surface layer: 1 – a calculated plot of the tangential residual stresses; 2 – a plot of residual stresses obtained experimentally (by mechani- cal destructive method); – residual stresses obtained by X-ray determination a b