IMPROVEMENT OF SURFACE LAYER QUALITY PARAMETERS OF STEEL PARTS AFTER NITROCARBURIZING BY ELECTROSPARK ALLOYING METHOD. Part 1. FEATURES OF THE STRUCTURAL STATE AND TOPOGRAPHY OF STEEL SURFACES AFTER NITROCARBURIZING

The paper analyses modern methods for improving the surface quality of steel parts of nuclear power plant pumps. The aim of the work was to improve the technology of nitrocarburisation by the method of electrospark alloying (ESA) by studying the effect of the ESA process performance on the quality parameters of the formed surfaces. As a result of the studies, the dependence of the quality parameters of the surfaces of steel parts during nitrocarburizing by the ESA method on the energy parameters of the equipment (discharge energy Wp) and the technological parameters of the process (productivity Q) was stablished. Experimental studies have shown that as Wp increases, the thickness of the hardened layer, its microhardness and continuity, and surface roughness grow. As Q decreases, the thickness, microhardness and continuity of the hardened layer rise, while the roughness remains practically unchanged. The proposed technology can be recommended for implementation in manufacturing.