This paper presents the results of a study on a new coating method for alloy steel. The coatings were synthesized on the surface of H21 die steel through a combination of thermal-chemical treatment (TCT) and electron beam processing (EBP). A paste containing boron and aluminum was applied to the test samples which were then heated to accelerate the diffusion process. After 2 h at 950 °C, the diffusion layers were found to be 120 μm thick, and after 2 h at 1050 °C, they were 580 μm thick. The subsequent EBP led to a complete transformation of the primary diffusion layer and an increase in thickness to 1.6 mm. XRD analysis showed significant differences in composition before and after EBP and the presence of tungsten and iron borides. It was also found that the distribution of microhardness and composition over the layer thickness had a more favorable profile after EBP.

This work investigates the effect of boriding and thermo-reactive deposition on 15B30 steel. The results presented in the paper show that these thermochemical treatments produce boride and carbide rich layers that improve surface hardness and wear resistance, and they do so without the adverse effects of adding more boron to the alloy.

Gray cast iron is primarily used for its low cost, high damping capacity, and excellent machinability. These properties are attributed to the presence of free graphite and the high fluidity of the molten metal, which allows for the easy casting of complex parts with thin walls. Applying suitable coatings can enhance wear resistance and broaden the material's range of applications. Niobium carbide, known for its high hardness, is a promising candidate for this purpose. In this study, samples of gray cast iron with the composition 3.47% C, 2.39% Si, 0.55% Mn, 0.15% Ni, 0.65% Cu, and the balance Fe were subjected to a niobizing powder thermo-reactive diffusion treatment. The coating mixture consisted of ferro-niobium, NH 4 Cl, and Al 2 O 3 , and the treatment was conducted at 900 °C for 2 hours. The resulting layers exhibited hardness values of 2000 HV, characteristic of niobium carbides. Micro-adhesive and micro-abrasive wear tests showed a significant increase in wear resistance due to this treatment.