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Comparison of the abrasion wear resistance of the laser alloyed hot work tool steels

Dobrzański L., Jonda E., Labisz K.

Archives of Materials Science and Engineering

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2012

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Vol. 55, nr 2

85-92

EN

Purpose: The paper presents the comparison of the abrasion wear resistance of the laser alloyed hot work tool steels X40CrMoV5-1 and 32CrMoV12-28. Design/methodology/approach: The tribological wear relationships using pin-on-disc test were specified for surface layers subject to laser treatment, determining the friction coefficient, and mass loss of the investigated surfaces. Findings: The performed investigations leads to the conclusions that for both types of steels - X40CrMoV5-1 and 32CrMoV12-28 the wear resistance measured using pin-on-disc, wear resistance test in the metal - metal arrangement, and wear resistance test in the metal - ceramic material arrangement, the wear resistance increases together with the hardness of the surface layer. This relationship is valid for all types of ceramic powders used. It is characteristic for the obtained surface layers, that the high roughness, multiple pores, irregularity, and flashes at the borders increases also together with the increasing of the laser power. Research limitations/implications: In order to evaluate with more detail the possibility of applying these surface layers in tools, further investigations should be concentrated on the determination of the thermal fatigue resistance of the layers. Practical implications: The alloyed layers which were formed on the surface of the hot work steels have shown significant improvement concerning properties. Good properties of the laser treatment make these layers suitable for various technical and industrial applications. Originality/value: A modification of tool steels surface using a laser beam radiation, as well as coating them with special pastes containing carbide particles allows the essential improvement of the surface layer properties - their quality and abrasion resistance, decreasing at the same time the surface quality, what is dependent on the processing parameters such as energy of impulse and the time of its work.

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Mechanical and tribological properties of the surface layer of the hot work tool steel obtained by laser alloying

Dobrzański L. A., Jonda E., Križ A., Lukaszkowicz K.

Archives of Materials Science and Engineering

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2007

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Vol. 28, nr 7

389-396

EN

Purpose: The paper presents results on the mechanical and tribological properties examinations of the X40CRMoV5-1 hot work alloy tool steel alloyed with carbide powders using the high power diode laser (HPDL). Design/methodology/approach: Metallographic examinations of the material structures after laser alloying of their surface layer were made on light microscope. The tribological wear relationships using pin-on-disc test were specified for surface layers subject to laser treatment, determining the friction coefficient, and mass loss of the investigated surfaces. Hardness tests were made with Rockwell method in C scale on specimens subjected to the standard heat treatment and alloyed using the high power diode laser at various parameters. X-ray diffraction (XRD) technique was used to investigate crystalline structure and phases in the layers. Findings: Metallographic examinations carried out on the light microscope confirm that the structure of the material solidifying after laser remelting is diversified, which is dependant on the solidification rate of the investigated steels. The investigations carried out made it possible to state that due to the heat treatment and remelting of the X40CrMoV5-1tool steel with the WC, TaC or TiC powders it is possible to obtain the high quality surface layer with no cracks and defects and with hardness significantly higher than the substrate metal. Research limitations/implications: In order to evaluate with more detail the possibility of applying these surface layers in tools, further investigations should be concentrated on the determination of the thermal fatigue resistance of the layers. Practical implications: The alloyed layers which were formed on the surface of the hot work steel have shown significant improvement. Good properties of the laser treatment make these layers suitable for various technical and industrial applications. Originality/value: A modification of tool steels surface using a laser beam radiation, as well as coating them with special pastes containing carbides particles such as tungsten, tantalum and titanium allows the essential improvement of the surface layer properties-their quality and abrasion resistance, decreasing at the same time the surface quality.

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Structure and tribological behavior of surface layer of laser modified X40CrMoV5-1 steel

Dobrzański L. A., Jonda E., Lukaszkowicz K., Križ A.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 18, nr 1-2

343--346

EN

Purpose: The paper presents the effect of alloying with WC, TaC and TiC on structure and mechanical properties of the X40CrMoV5-1 steel surface layer using the HPDL (High Power Diode Laser). Design/methodology/approach: The microstructure of the alloyed layers which were formed on the surface of the investigated hot work steel was examined using optical microscope. The tribological wear relationships using pin-on-disc test were specified for surface layers subject to laser treatment, determining the friction coefficient, and mass loss of the investigated surfaces. X-ray diffraction (XRD) technique was used to investigate crystalline structure and phases in the layers. Findings: The metallographic investigations on light microscope show that during alloying the X40CrMoV5-1 hot work tool steel with the WC, TaC and TiC powder layer the obtained run face is characteristic of the high roughness, multiple pores, irregularity, and flashes at the borders. The changes of the surface layers hardness formed as a result of remelting and alloying with ceramic powders containing carbides are accompanied with the increased tribological properties. Research limitations/implications: In order to evaluate with more detail the possibility of applying these surface layers in tools, further investigations should be concentrated on the determination of the thermal fatigue resistance of the layers. Practical implications: The alloyed layers which were formed on the surface of the hot work steel have shown significant improvement. Good properties of the laser treatment make these layers suitable for various technical and industrial applications. Originality/value: Structural and tribological behaviour of surface layer achieved by alloying and remelting using high diode power laser and selected ceramic powders were compared.

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Structure and properties of surface layers obtained by alloying of the hot work tool steels

Dobrzański L. A., Polok A., Jonda E.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 17, nr 1-2

329--332

EN

Purpose: The aim of the present work was to study the microstructure and properties produced after laser alloying of the 55NiCrMoV7 and X40CrMoV5-1 an alloy hot-work tool steels. Design/methodology/approach: Structure investigation was performed using the light microscope Leica MEF4A supplied by Zeiss. Phase composition and crystallographic structure were determined by the X-ray diffraction method using the DRON 2.0. The measurements of microhardness have been performed using Shimadzu microhardness intender equipped with electronic sensor that allows the direct readout of the hardness values. Findings: The metallographic investigations on light microscope show that steel after laser remelting can be characterized by a dendrite structure. Metallographic examinations on the scanning microscope with the EDX attachment confirm the occurrence of the niobium carbides in the surface layer of the investigated steels. Research limitations/implications: In order to evaluate with more detail the possibility of applying these surface layers in tools, further investigations should be concentrated on the determination of the thermal fatigue resistance of the layers. Practical implications: The surface layer of the hot work steel alloyed with ceramic powder have good properties and make possibility for uses it in various technical and industrial applications. Originality/value: The microstructure and properties of the surface layer of the 55NiCrMoV7 and X40CrMoV5-1 hot-work tool steels alloying with ceramic powder were compared.

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Comparison of the abrasion wear resistance of the X40CrMoV5-1 and 55NiCrMoV7 hot work tool steels with their surface layer enriched with the ceramic powders

Dobrzański L. A., Jonda E., Polok A.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 15, nr 1-2

32--38

EN

Purpose: In the paper there are presented the results of the influence of laser remelting parameters on the properties of the surface layer of the X40CrMoV5-1 and 55NiCrMoV7 hot work steel, using the high power diode laser (HPDL). The aim of this work was to compare the abrasion wear resistance of the X40CrMoV5-1 and 55NiCrMoV7 hot work tool steel surface layers enriched with the TiC, WC and VC ceramic powders. The surface layers of hot work tool steel remelted with a diode laser beam have been metallographically examined and analyzed with the use of a hardness testing machine. Design/methodology/approach: The high power diode laser (HPDL) and ceramic powders WC, VC and TiC were used. Remelting and alloying processes were carried out at the constant remelting rate and focus shape, varying the laser beam power for the alloyed test pieces in the range from 1,2 – 2,3 kW. Findings: On the basis of the wear abrasion tests carried out on 55NiCrMoV7 and X40CrMoV5-1 steels it could be ascertained that each of those steels is characterized by different resistance for the same powders and the power of the laser beam. In the case of employing 1,2 kW laser, the surface layer formed using the majority of the investigated portions undergoes a total wear during the wear-rate test which also causes the wear of the initial material. When 2,3 kW is employed, the surface layers have crack and microcrack defections which decrease the resistance to the abrasion. The smallest mass loss for 55NiCrMoV7 steel among all the analyzed cases has been observed for the surface layers alloyed with TiC powder, at the of the laser beam power of 2,3 kW and for WC powder at 1,2 kW laser beam power. For the X40CrMoV5-1 steel the smallest mass decrement has been observed forthe steel alloyed with WC powder at 1,2 kW laser beam power and VC powder at 1,6 kW laser beam power. Practical implications:The investigations showed that as a result of the applied laser processing there is the increase in the hardness and resistance to abrasion of the surface layers in relation to the output material. Originality/value: Wear resistance and hardness of two hot work tool steels were compared.