Investigations include alloying the X38CrMoV5-3 hot-work tool steel surface layer with
the tungsten carbide, using the high power diode laser (HPDL). The tungsten carbide ceramic
particles of the medium grain size according to FSSS = 50 /m were introduced using the rotor
conveyer to improve the properties of the surface layer. The powder feed rate was set at the steady
level of 8.64g/min. Remelting and alloying were carried out several times in the laser power range
of 1.2 – 2.3 kW in the remelting/alloying, alloying/remelting sequences. The structural mechanism
was determined of gradient layer development, effect was studied of alloying parameters, gas
protection method, and powder feed rate on its mechanical properties, and especially on its
hardness, abrasive wear resistance, and roughness. Structure changes were revealed consisting, in
particular, in its refining, and also hardness and microhardness changes in comparizon to the nonremelted
steel. Examination results obtained with the EDX microanalysis, surface and linear
analysis of the chemical composition, as well as the X-ray qualitative phase analysis are presented.