In recent years the interest in the development of new protective coatings with improved functional properties for machine parts’ surface have been of great fundamental and applied importance. The current study is devoted to the creation of coatings based on boron and aluminium on the surface of alloy steel using a cutting-edge method, combining thermal-chemical treatment (TCT) and subsequent electron beam processing (EBP). TCT was carried out in treatment pastes based on boron carbide and aluminum at 950°C and 1050°C for 2 hours. As a result of processing, diffusion layers with a thickness of up to 120 μm and 580 μm were formed on the steel surface after TCT at 950°C and 1050°C respectively. The subsequent EBP led to a complete transformation of the primary diffusion layer and an increase in its thickness to 1.6 mm. XRD analysis showed significant differences in composition before and after EBP: new compound, such as tungsten borides (WB, W2B9) and iron boride (Fe2B) were detected. In addition, it was determined that the distribution of microhardness and elemental composition (B, Al, W) over the layer thickness after EBP had a more favorable profile without significant fluctuations compared to the sample after TCT. The concentration of Al decreased significantly after EBP. It dropped from 18% after TCT to a low of 1%.