Study of the Formation of the Alloyed Surface Layer During Plasma Heating of Mixtures of Cu-Sn/CrXCY Alloys

In this work, to assess the possibility of obtaining an alloyed layer by plasma heating of the mixture of the PRV-BrO10 alloy and the coating of the welding electrode OK 84.78. The study of the structure is given using the optical microscope MET-2 and the measurement of microhardness - hardness testers of the HMV-G series. It is established that with a thin layer of pre-coating, the coatings are completely saturated, and with a thick layer - the formed zones are different in microstructure and microhardness. In the case of 0.25 mm pre-coating thickness, the addition of chromium carbide leads the strong increasing of the hardness compared to tin-bronze alone. In the case of 0.50 mm pre-coating thickness, for the upper soft zone rich in copper, the average microhardness value is below 250 HV, and for hard particles in this zone in the range of 500-700 HV, the lower saturated zones have high hardness in a wide range (400- 700 HV). The slow scanning speed of the torch and a thick layer of pre-coating are the reason for incomplete saturation and the appearance of defects on the surface of St3 steel.