Structure and properties of boride layers on low-carbon steel after plasma alloying with boron carbide

Abstract

Wear is known to limit the life of tools and machines. To achieve high wear resistance, the hard phases must be individually adapted to the tribological system and especially to the interaction with abrasive objects. Comparison of the hardness of carbides, nitrides and borides of the same stoichiometry shows that borides usually have the highest hardness. Plasma doping with boron is an effective way to obtain boride layers with high wear resistance. In the work, a study of the microstructure, determination of the chemical composition in local places, measurement of microhardness and testing for adhesion to the substrate of the doped layer after processing were carried out. Based on the results of the research, it was found that the technology of plasma alloying with boron makes it possible to obtain a boride layer with high hardness and good adhesion to the substrate. According to the results of the study, the layer consists of several characteristic zones: hypereutectic, eutectic and heat-affected zones. The highest microhardness value of the alloyed layer is 1174 HV. It is noted that the hardening depth is 1.5 mm and is 5—6 times higher compared to the diffusion borated layer.