Modelling of surface layer of the 32CrMoV12-28 tool steel using HPDL laser for alloying with TiC powder

Purpose: In this work are presented the performed investigation for the reason to determine the laser treatment parameters, for example the laser power to achieve a high value of layer hardness for protection of this hot work tool steel from losing their work stability and to make the tool surface more resistant for work. The purpose of this work was also to determine technological conditions for remelting the surface layer with HPDL. Design/methodology/approach: The research way results of new laser treatment methodology applied in metal surface technology are presented and discussed. There is presented laser treatment with remelting of hot work tool steel 32CrMoV 12-28 with ceramic powders especially titanium carbide - TiC, as well as results of laser remelting influence on structure and properties of the surface of the hot work steel, carried out using the high power diode laser (HPDL). Special attention was devoted to monitoring of the layer morphology of the investigated material and on the particle occurred. Optical and scanning electron microscopy was used to characterize the microstructure and intermetallic phases occurred. Findings: A surface layer was comming into existence without cracks and defects as well as has a considerably higher hardness value compared to the non remelted material. The hardness value increases according to the laser power used so that the highest power applied gives to highest hardness value in the remelted layer. Research limitations/implications: Four laser powers were choused and implicated by one process speed rate. Also one powder in form of TiC was used for alloying with the particle size of 10 micrometres. Practical implications: The investigation helps to use the laser treatment technique for alloying of hot work tool steel with different ceramic particles. Originality/value: The scientific reason of this work is the applying of High Power Diode Laser (HPDL) for improvement of steel mechanical properties, especially the surface.