Papers by Author: Andrzej Klimpel

Abstract: This paper presents the investigation results of laser alloying and the influence on structure and properties of the surface of the 32CrMoV12-28 hot work steel, carried out using the high power diode laser (HPDL). Structure changes were determined in the work, especially structure fragmentation. Also hardness investigation of the different remelting areas was performed. The reason of this work was also to determine the laser treatment parameters, particularly the laser power, to achieve good work stability and to make the tool surface more resistant for work extremal conditions. Based on microstructural examinations of the obtained material, the distribution of the reinforcing ceramic particles in the hot work tool steel was revealed. Tungsten carbide WC powder was used for alloying. The remelted layers which were formed on the surface of the investigated hot work steel were examined metallographically and analyzed using a hardness testing machine.

Abstract: 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 Bm 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 comparison to the non-remelted steel. Examination results obtained with the EDX microanalysis, surface and linear analyses of the chemical composition, as well as the X-ray qualitative phase analysis are presented.

Abstract: This work presents the investigation results of laser remelting and alloying especially the laser parameters and its influence on the structure and properties of the surface of the 32CrMoV12-28 hot work steel, using the high power diode laser (HPDL). As a result structure changes in form of fragmentation were determined. The reason of this work was to determine the optimal laser treatment parameters, particularly the laser power to achieve good layer hardness for protection of this hot work tool steel from losing their work stability and to make the tool surface more resistant to action in hard conditions. For alloying the tantalum carbide, tungsten carbide and vanadium carbide powders were used. For investigations hardness measurements of the different remelting areas were performed. The remelted layers which were formed in the surface of investigated hot work steel were examined metallographically and analyzed using light and electron microscope. Three phases of carbides, TaC, VC and WC, were observed.

Abstract: 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.