This article describes the microstructure features, microhardness, and elemental phase distribution in ledeburitic 1.7%C–14%Cr–3%Mn–3%Si–1%Ni–0.6%V–1.2%B steel fabricated by pulsed plasma deposition in comparison with conventional sand casting. An electrothermal axial plasma accelerator is used as plasma source with following processing parameters: voltage is of 4.0 kV, the discharge current amplitude is up to 18 kA, the working environment is air, the working pressure is atmospheric, the cathode is the 1.7%C–14%Cr–3%Mn–3%Si–1%Ni–0.6%V–1.2%B steel. The work is carried out using the optical and scanning microscopies, EDS, XRD, and microhardness measurements. As found after sand casting, the steel contains in the structure large (10–40 $\mu$m) primary (Fe$_{3.8}$Cr$_{2.9}$Mn$_{0.3}$)$_7$C$_3$ carbide, (Fe$_{1.4}$Cr$_{0.6}$Mn$_{0.1}$)$_{2}$(С,B) and (Fe$_{3.3}$Cr$_{1.5}$Mn$_{0.2}$)$_5$(С,B$_2$)$_3$ carboborides as well as ‘austenite + М$_7$С$_3$’ and ‘austenite + М$_7$С$_3$ + М$_х$(С,B)$_y$’ eutectics. The volume fraction of carbides and carboborides is of 44%. Pulsed plasma treatment leads to formation of steel coating of oversaturated solid solution with the microhardness of 643–932 $HV$. Post-plasma heat treatment (quenching from 900°C) results in solid-state reaction of the (М$_7$С$_3$) carbide and (М$_2$(С,B), М$_5$(С,B)$_3$) carboborides’ precipitation from the solid solution. This one leads to formation of large amount of dispersed precipitates of mean size of 0.7 $\mu$m reflecting substantial (ten folds) refinement of carbide and carboborides in comparison with the sand cast steel. Pulsed plasma deposition is accompanied with the saturation of steel by carbon due to the erosion of dielectric chamber walls (bakelite–paper composite) under high-current discharge. This one causes the increase of the carbides and carboborides volume fraction by 10.5% relative to convention casting. Post-plasma heat treatment provides the increase of microhardness up to 885–1100 $HV$.