Application of high power diode laser (HPDL) for alloying of X40CrMoV5-1 steel surface layer by tungsten carbides

Investigations included alloying experiments on the X40CrMoV5-1 hot-work steel with the high power diode laser. Tests were made using the high power diode laser (HPDL) in the technological process of alloying of the surface layer with the tungsten carbides. The effect of alloying parameters, the gas shielding method, and thickness of paste coatings applied onto the surface of the steel, on structure and properties of its surface layer, as well as on stresses, strains, and also remelting geometry and shape. The influence of the technological conditions on volume portions and forms of carbides and their effect on the mechanical properties of the surface layer, and especially its hardness, wear resistance and roughness was tested. Dependence of the microhardness changes, on the degree of the laser beam influence on the treated surface, and mostly on the hardness increase in the alloyed layer is presented. The tribological wear relationships were specified for surface layers subjected to laser treatment, determining the friction coefficient, mass loss, and profile shapes of the investigated surfaces. Guidelines for alloying with the tungsten carbide of the X40CrMoV5-1 steel surface using the high power diode laser feature the outcome of the investigation aimed at obtaining its optimum mechanical and working properties.