M. Piec

Laser Alloying with WC Ceramic Powder in Hot Work Tool Steel Using a High Power Diode Laser (HPDL)

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.

Structure and Properties of the 32CrMoV12-28 Steel Alloyed with WC Powder Using HPDL Laser

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.

Diode Laser Modification of Surface Gradient Layer Properties of a Hot-Work Tool Steel

The objective of the present work was to study the modification of the microstructure of hot-work tool steels X40CrMoV5-1 and X38CrMoV5-3 during the surface modifying by means of laser technology. This treatment aims to harden and alloy the steel surface which had been previously coated with tungsten carbide (WC) and were introduced using the rotor conveyer to improve the properties of the surface layer. The fine grained, dendritic structure occurs in the remelted and alloyed zone with the crystallization direction connected with the dynamical heat abstraction from the laser beam influenced zone. The fine grained martensite structure is responsible for the hardness increase of the alloyed layer.

Modelling of properties of the alloy tool steels after laser surface treatment

This paper presents the investigation results of the computer modelling of the surface layer hardness of hot work tool alloy steel alloyed with the ceramic powders using the High Power Diode Laser (HPDL). Laser treatment by remelting or alloying with the carbides was employed for improvement of the surface layer properties of tools made from the hot work tool steels. The developed model of the neural network make predicting possible for the surface layer hardness values. Further investigations should be concentrated on computer modelling of microhardness and resistance wear abrasion using the artificial neural networks. The surface layer of the hot work steel alloyed with ceramic powder using the HPDL have good properties and makes it possible for using in various technical and industrial applications. The artificial neural networks were used to determine the technological effect of laser alloying on hardness of the hot work tool steels. [Received 10 January 2007; Accepted 12 July 2007]

Structure and Properties of Gradient Layers Using High Power Diode Laser

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.

Laser modification of hot-work tool steels gradient layers P551

The objective of the present work was to study the modification of the microstructure of hot-work tool steels X40CrMoV5-1 and X38CrMoV5-3 during the surface modifying by means of laser technology. The aim of such treatment was to harden and alloy the steel surface which had been previously coated with tungsten carbide (WC) and were introduced using the rotor conveyer to improve the properties of the surface layer. Development of the surface layer was observed in which one can distinguish the remelted zone, heat-affected zone and the transient zone. The fine grained, dendritic structure occurs in the remelted and alloyed zone with the crystallization direction connected with the dynamical heat abstraction from the laser beam influence zone.The fine grained martensite structure is responsible for hardness increase of the alloyed layer. It has the important cognitive significance and gives grounds to the practical employment of these technologies for forming the surfaces of new tools and regeneration of the used ones.The objective of the present work was to study the modification of the microstructure of hot-work tool steels X40CrMoV5-1 and X38CrMoV5-3 during the surface modifying by means of laser technology. The aim of such treatment was to harden and alloy the steel surface which had been previously coated with tungsten carbide (WC) and were introduced using the rotor conveyer to improve the properties of the surface layer. Development of the surface layer was observed in which one can distinguish the remelted zone, heat-affected zone and the transient zone. The fine grained, dendritic structure occurs in the remelted and alloyed zone with the crystallization direction connected with the dynamical heat abstraction from the laser beam influence zone.The fine grained martensite structure is responsible for hardness increase of the alloyed layer. It has the important cognitive significance and gives grounds to the practical employment of these technologies for forming the surfaces of new tools and regeneration of the ...