Mechanical properties of the surface layer of the laser alloyed 32CrMoV12-28 steel

Purpose: In this paper it was investigated the influence of the laser treatment, first of all the laser power, to the mechanical properties and structure of the steel surface layer alloyed with different ceramic powders. The purpose of this work was also to determine technological and technical conditions for remelting the surface layer with HPDL. Design/methodology/approach: This paper presents and discusses the main methodology results of new laser treatment techniques applied in metal surface technology are. There is presented laser treatment with remelting of hot work tool steel 32CrMoV12-28 with ceramic powders especially carbides, oxides and nitrides 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). Optical and scanning electron microscopy was used to characterize the microstructure and intermetallic phases occurred. Findings: A surface layer was coming 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 choused laser powers were applied for alloying and implicated by one process speed rate. The powders which were used for alloying were of the particle size in the range of 5 to 10μm. Practical implications: This work helps to use the laser treatment technique for alloying and remelting of hot work tool steel. Originality/value: The originality of this work is based on applying of High Power Diode Laser for improvement of steel mechanical properties.