ANALYSIS OF QUALITY COMPLEX SULFOCEMENTED COATINGS OBTAINED BY ELECTROSPARK ALOYING

Abstract

The analysis of quality surface layers after sulfocementation by electrospark alloying is carried out. Metallographic studies are shown that the typical white layer of electrospark coatings is not pronounced. The surface layer consists of a diffusion zone, the thickness of which increases with increasing discharge energy, and the base metal. Durometric studies of sulfocemented coatings are shown that two zones are formed in the surface layer: zone of low microhardness and hardened layer. The surface layer is saturated with sulfur, according to X-ray spectrum analysis. Sulfur accumulates on the metal surface to depth of 30 μm, its concentration at this distance is about 0.4%. With an increase in the discharge energy, the hardness, the depth of the layer of reduced microhardness and the hardened layer, as well as the surface roughness increase.