Structural-technological model of wear for surfacing materials based on Fe–Cr–Ni–Мо and Fe–Co–Ni–Мо

The paper presents the results obtained when studying the structure of surfacing materials based on martensitic-aging Fe–Cr– Ni–Мо и Fe–Co–Ni–Мо alloys obtained by plasma powder surfacing. Silicon was chosen as an alloying element, which made it possible to significantly improve the technical and economic performance of martensitic-aging materials. A comparison of martensitic-aging steels with high-carbon steels showed that the former provide an advantage as a wear-resistant material due to their increased resistance to crack propagation. Microscopic analysis, X-ray diffraction analysis and electron microprobe analysis were used for the research. Surfacing materials were tested for wear and internal friction. Silicon oxide particles and chromium and molybdene silicides involved in the process of alloying material strengthening were found during the experiments. Silicide particle density was determined that varies depending on the amount of silicon in the material. The effect of the silicon content on the material hardness was considered. The data obtained on the structure and phase composition of Fe–Cr–Ni–Мо и Fe–Co–Ni–Мо compounds doped with silicon in both the initial and aged states made it possible to suggest a structural-physical model of their hardening in the course of aging. Results of the experiments showed that the heat treatment process actively influences the wear rate and weight wear reducing their values that is typical for both Fe–Cr–Ni–Мо and Fe–Co–Ni–Мо alloys. Based on these data, a structural-technological model of wear was obtained for the surfacing materials studied.