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1
Content available remote Laser treatment with 625 Inconel powder of hot work tool steel using fibre laser YLS-4000
Dobrzański L. A., Jonda E., Pakieła W., Dziekońska M.
Journal of Achievements in Materials and Manufacturing Engineering
|
2018
|
Vol. 91, nr 2
60--67
EN
Purpose: The purpose of this investigation was to determine the changes in the surface layer (Inconel 625), obtained during the laser treatment of tool-steel alloy for hot work by the use high-power fibre laser. Design/methodology/approach: Observations of the layer structure, HAZ, and substrate material were made using light and scanning microscopy. The composition of elements and a detailed analysis of the chemical composition in micro-areas was made using the EDS X-ray detector. The thickness of the resulting welds, heat affected zone (HAZ) and the contribution of the base material in the layers was determined. Findings: As a result of laser cladding, using Inconel 625 powder, in the weld overlay microstructure characteristic zones are formed: at the penetration boundary, in the middle of weld overlay and in its top layer. It was found that the height of weld overlay, depth of penetration, width of weld overlay and depth of the heat affected zone grows together with the increasing laser power. Practical implications: Laser cladding is one of the most modern repair processes for eliminating losses, voids, porosity, and cracks on the surface of various metals, including tool alloys for hot work. Laser techniques allow to make layers of materials on the repaired surface, that can significantly differ in chemical composition from the based material (substrate material) or are the same. Originality/value: A significant, dynamic development in materials engineering as well as welding technologies provides the possibility to reduce the cost of production and operation of machinery and equipment, among others by designing parts from materials with special properties (both mechanical and tribological) and the possibility of regeneration of each consumed element with one of the selected welding technologies.
2
Content available remote Microstructure and properties of the hot work tool steel gradient surface layer obtained using laser alloying with tungsten carbide ceramic powder
Jonda E., Labisz K., Dobrzański L. A.
Archives of Materials Science and Engineering
|
2016
|
Vol. 78, nr 1
37--44
EN
Purpose: The aim of the paper is to present the innovatory investigation results of the impact of laser treatment consisting of multiple remelting and alloying using tungsten carbide ceramic powder on the microstructure and properties of hot work tool steel X40CrMoV5-1 surface layer. Design/methodology/approach: Laser heat treatment allows the production of gradient surface layer with a thickness reaching from of tenths of a millimetre even to few millimetres with specific functional properties, including high hardness and abrasion resistance, while maintaining the properties of the substrate material. Findings: Preliminary investigations of the effects of laser radiation on steel surface have showed, that in the surface layer there occur changes concerning the microstructure as well as in the chemical composition different from those occurring during conventional heat treatment. Research limitations/implications: There was determined the effect of laser power on the remelting depth, the depth of the heat affected zone and the width of the laser tray face. There was also measured and compared to the hardness and roughness of the steel processed by remelting with different process parameters. Practical implications: The current application areas for hot work tool steels are constantly growing, and the intensive development of techniques requires the use of new technologies, what leads to production of specific surface layer on materials, in order to meet the extremely difficult working conditions of modern tools. Originality/value: The effect of a HPDL laser melting on the hot work tool steel, especially on their structure and hardness has been studied.
3
Content available Wpływ zmęczenia cieplnego na udarność stali narzędziowej do pracy na gorąco Orvar Supreme
Lulkiewicz J., Pachutko B., Gąsiorkiewicz M., Szkudelski S., Garczyński Z., Ziółkiewicz S.
Obróbka Plastyczna Metali
|
2015
|
T. 26, nr 1
21--32
PL
W artykule przedstawiono wyniki badań zmęczenia cieplnego stali do pracy na gorąco Orvar Supreme (odpowiednik stali WCLV) na stanowisku badawczym zaprojektowanym w Instytucie Obróbki Plastycznej. Stanowisko składało się głównie z następujących elementów: nagrzewnicy indukcyjnej, układu chłodzenia i pirometrów. Pęknięcia cieplne wytworzono na próbkach prostopadłościennych, które wymiarami były zbliżone do standardowych próbek udarnościowych, ale nie miały karbu. Cykle nagrzewania próbki prowadzono w temperaturze wynoszącej: 500°C, 600°C i 650°C. Liczba cykli wynosiła 1 tysiąc i 5 tysięcy. Nieniszczące pomiary łącznej długości pęknięć cieplnych na krawędzi próbki wykonano za pomocą tomografu komputerowego w Instytucie Odlewnictwa w Krakowie. Próbę udarności sposobem Charpy’ego wykonano w temperaturze wynoszącej: 500°C, 600°C i 650°C na próbkach poddanych 1 tysiącowi oraz 5 tysiącom cykli nagrzewania. W badaniach stosowano młot wahadłowy o początkowej energii uderzenia wynoszącej 300 J. Przeprowadzono pomiary głębokości pęknięć na przekrojach próbek, po wykonaniu prób udarności oraz przeanalizowano wyniki otrzymanych badań. Badania te wykonano na próbkach poddanych cyklicznemu nagrzewaniu w temperaturze 600°C i 650°C. W wyniku cyklicznego nagrzewania próbek do temperatury 500°C przy 5 tysiącach cykli nie stwierdzono pęknięć cieplnych. Nagrzanie próbek poddanych cyklicznemu zmęczeniu cieplnemu w temperaturze 500°C i 650°C spowodowało zwiększenie energii uderzenia w porównaniu do próbek ulepszonych cieplnie. W temperaturze 600°C wystąpił efekt zwiększenia twardości, co skutkowało zmniejszeniem energii uderzenia potrzebnej na złamanie próbki udarnościowej. Najdłuższe pęknięcia otrzymano na próbkach poddanych 5 tysiącom cykli nagrzewania w temperaturze wynoszącej 650°C.
EN
The paper presents the results of investigation of thermal fatigue of Orvar Supreme steel (equivalent of WCLV steel) on a test stand designed by the Metal Forming Institute. The stand consisted of the following main elements: induction heater, cooling system of pyrometers. Thermal cracks have been made on rectangular samples with the dimensions close to those of standard impact test pieces but without notch. The heating cycles of the sample have been performed at the temperature of 500oC, 600oC, and 650oC. The number of cycles was 1 thousand and 5 thousand. Non-destructive measurements of the total length of thermal cracks on the sample edge have been performed by means of a computer tomograph by the Institute of Casting in Cracow. Charpy impact test has been performed at the temperature of 500oC, 600oC and 650oC on samples subjected to a thousand and 5 thousand heating cycles. In the tests, Charpy pendulum machine with initial impact energy of 300 J has been used. The crack depths have been measured on the cross sections of samples after impact tests and the test results have been analysed. The tests have been performed on samples subjected to cyclic heating at the temperature of 600oC and 650oC. As a result of the cyclic heating of the samples up to the temperature of 500oC, at 5 thousand cycles, thermal cracks have not been found. Heating has caused increase of the impact energy as compared to toughened samples. At the temperature of 600oC, the effect of hardness increase has taken place, which has resulted in reduction of the energy necessary to break the impact test piece. The longest cracks have been obtained on the samples subjected to 5 thousand heating cycles at 650oC.
4
Content available The Numerical Analysis of the Phenomena of Superficial Hardening of the Hot-Work Tool Steel Elements
Bokota A., Kulawik A., Szymczyk R., Wróbel J.
Archives of Metallurgy and Materials
|
2015
|
Vol. 60, iss. 4
2763--2772
EN
In the paper the complex model of hardening of the hot-work tool steel is presented. Model of estimation of phase fractions and their kinetics is based on the continuous heating diagram (CHT) and cooling diagram (CCT). Phase fractions which occur during the continuous heating and cooling (austenite, pearlite or bainite) are described by Johnson-Mehl (JM) formula. To determine of the formed martensite the modified Koistinen-Marburger (KM) equation is used. Model takes into account the thermal, structural, plastic strains and transformation plasticity. To calculate the plastic strains the Huber-Mises plasticity condition with isotopic hardening is used. Whereas to determine transformations induced plasticity the Leblond model is applied. The numerical analysis of phase compositions and residual stresses in the hot-work steel (W360) element is considered.
PL
W pracy przedstawiono kompleksowy model hartowania stali narzędziowej do pracy na gorąco. Model szacowania ułamków faz oraz ich kinetyki oparto na wykresach ciągłego nagrzewania (CTPA) oraz chłodzenia (CTPc). Ułamki faz powstałych podczas ciągłego nagrzewania i chłodzenia (austenit, perlit lub bainit) wyznaczane są równaniem Johnsona- Mehla. Do określenia tworzącego się martenzytu wykorzystano zmodyfikowane równanie Koistinena i Marburgera. W modelu uwzględniono odkształcenia cieplne, strukturalne, plastyczne oraz odkształcenia transformacyjne. Do wyznaczania odkształceń plastycznych zastosowano warunek plastyczności Hubera-Misesa ze wzmocnieniem izotropowym, natomiast do wyznaczenia odkształceń transformacyjnych wykorzystano model Leblonda. Dokonano analizy numerycznej składu fazowego oraz naprężeń hartowniczych w elementach wykonanych ze stali narzędziowej do pracy na gorąco (W360).
5
Content available Niskocyklowe zmęczenie cieplne stali narzędziowej WCLV
Gronostajski Z., Hawryluk M., Marciniak M.
Obróbka Plastyczna Metali
|
2013
|
T. 24, nr 4
233--242
PL
W artykule przedstawiono wyniki badań odporności na pękanie stali narzędziowej WCLV w warunkach zmęczenia cieplnego. Przyjęta metodyka pracy łączy badania eksperymentalne oraz symulacje komputerowe. Opisano także wyniki badań jakościowych i ilościowych z przeprowadzonych prób eksperymentalnych w zależności od warunków temperaturowych oraz przedstawiono wyniki spadku twardości warstwy wierzchniej. Otrzymane wyniki badań oraz symulacja komputerowa stanowiska badawczego pozwolą na wyznaczenie charakterystyki zmęczenia cieplnego stali WCLV.
EN
This paper presents the results of crack resistance tests carried out on hot-work tool steel H13 in thermal fatigue conditions. The adopted research methodology combines experiments and computer simulations. Also the results of qualitative and quantitative tests for different temperature conditions, showing the cycle temperature to be a factor contributing to a decrease in surface layer hardness, are reported. The experimental results and computer simulations will be used to determine the thermal fatigue characteristic of steel H13.
6
Content available Premature cracking of dies for aluminium alloy die-casting
Pawłowski P., Bała P., Tokarski T., Krawczyk J.
Archives of Metallurgy and Materials
|
2013
|
Vol. 58, iss. 4
1275--1279
EN
Two identical dies for aluminium alloy die-casting failed prematurely because of a number of parallel cracks on the working surface. These cracks were of a mechanical nature related to incorrect microstructural banding orientation of the die core and related to improper heat treatment. The microstructural banding orientation was determined by metallographic examination of the specimens, which were cut from the dies along the three axes of the coordinate system. Scanning electron microscopy (SEM) examination of the fracture surfaces and along the crack path (including energy dispersive spectroscopy (EDS) analysis) indicated that the root cause of the premature cracking of the dies was improper heat treatment (quenching and tempering conditions). Additionally, resistance to fracture of the investigated specimens, as measured by the Charpy V-notch test, was five times lower than that required for the desired hardness.
PL
Dwie identyczne matryce do ciśnieniowego odlewania stopów aluminium zostały przedwcześnie wycofane z eksploatacji z powodu wystąpienia na ich powierzchniach roboczych szeregu równoległych pęknięć. Kierunek propagacji pęknięć pokrywał się z kierunkiem pasmowości mikrostrukturalnej a samo tworzenie się pęknięć było skutkiem niewłaściwej obróbki cieplnej matryc. Stwierdzono nieprawidłową orientację geometryczną matrycy względem kierunku włókien struktury pierwotnej. Badania przy użyciu skaningowego mikroskopu elektronowego z wykorzystaniem techniki EDS wykazały, że przyczyną powstawania pęknięć matryc była nieprawidłową przeprowadzona obróbki cieplna matryc.
7
Analiza dylatometryczna przemian fazowych podczas odpuszczania stali 56NiCrMo7
Dąbrowski R., Dziurka R.
Hutnik, Wiadomości Hutnicze
|
2012
|
Vol. 79, nr 10
748--752
PL
W artykule zaprezentowano oryginalny wykres CTPc° (czas – temperatura – przemiana) dla przemian zachodzących podczas odpuszczania stali narzędziowej do pracy na gorąco w gatunku 56NiCrMo7. Wykres wykonano dla wybranej temperatury austenityzowania równej 830 °C. Uzyskane wyniki zilustrowano za pomocą dylatogramu chłodzenia stali od 830 °C oraz dylatogramów nagrzewania ze stanu zahartowanego (odpuszczania) wraz z ich interpretacją. Na dylatogramach nagrzewania stwierdzono dwa wyraźne efekty dylatacyjne ujemne: pierwszy − pochodzący najprawdopodobniej od wydzielania węglika ε oraz drugi – związany z wydzielaniem cementytu stopowego (M3C). Ponadto, zarejestrowano wyraźny efekt dylatacyjny dodatni związany z przemianą austenitu szczątkowego. Nie zaobserwowano natomiast efektu dylatacyjnego dodatniego pochodzącego od niezależnego zarodkowania węglików typu MC. Uzyskane wyniki badań pozwolą zmodyfikować technologię odpuszczania narzędzi wykonanych z badanej stali.
EN
In this paper the original CHT diagram (Continuous - Heating - Transformation) during tempering of 56NiCrMo7 hot-work tool steel was presented. The diagram was prepared for the chosen austenitizing temperature (830 °C). To present the way of interpretation of the results, dilatograms of cooling the sample as well heating the samples from as-quenched state were studied. Two negative dilatation effects were found on the dilatograms of heating: first - related most probably to the precipitations of ε carbide and second – related to the precipitations of alloyed cementite (M3C). Moreover, the positive dilatation effect related to the transformation of the retained austenite was registered. The positive dilatations effect related to independent nucleation of the carbides of MC type was not observed. Obtained results will let work out the detailed technology of tempering of tools made of the investigated steel.
8
Content available remote 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
|
2012
|
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.
9
Kinetyka przemian fazowych przechłodzonego austenitu stali 56NiCrMo7 w warunkach izotermicznych
Dąbrowski R., Pacyna J., Dziurka R.
Hutnik, Wiadomości Hutnicze
|
2011
|
Vol. 78, nr 3
248-253
PL
W artykule przedstawiono wykres CTPi (czas - temperatura - przemiana przy chłodzeniu izotermicznym) stali narzędziowej do pracy na gorąco gatunku 56NiCrMo7. Wykres sporządzono dla wybranej temperatury austenityzowania równej 820 °C. Dla zilustrowania uzyskanych wyników zamieszczono dylatogramy w układzie dL/Lo = f(t), (gdzie: dL - zmiana długości próbki, Lo - długość początkowa, t - czas) wraz z krzywymi różniczkowymi dL/Lo/dt = f(t), na których wyznaczano czas do rozpoczęcia i zakończenia przemian austenitu w mikrostruktury dyfuzyjne i pośrednie. Ponadto, dokonano analizy zmian twardości i mikrostruktury próbek badanej stali po izotermicznym wytrzymywaniu i następnym chłodzeniu do temperatury pokojowej.
EN
In this paper the TTT diagram (Time-Temperature-Transformation upon isothermal cooling) of the hot-working tool steel grade 56NiCrMo7 is presented. The diagram has been obtained for austenitizing temperature of 820 °C. In order to illustrate the received results, the dilatometric curves L/Lo = f(t), (where : L/Lo - relative length change of the sample, t - time) and first derivative curves L/Lo/t = f(t), showing the start and finish times of the austenite transformations into different types of pearlitic and bainitic microstructures are shown presented. In addition, the microstructure analyses and hardness measurements were carried out.
10
Zmiany mikrostruktury i twardości stali 56NiCrMo7 w zakresie temperatur austenityzowania 700÷1000 °C
Dąbrowski R., Dziurka R.
Hutnik, Wiadomości Hutnicze
|
2010
|
Vol. 77, nr 6
290-296
PL
W artykule przedstawiono wyniki badań wstępnych stali narzędziowej gatunku 56NiCrMo7 do pracy na gorąco. Obejmowały one ocenę punktów przełomowych oraz mikrostruktury w stanie wyżarzonym. Dokonano również analizy zmian twardości oraz zmian zachodzących w mikrostrukturze stali w wyniku zmiany temperatury austenityzowania. Uzyskane wyniki badań stanowią przyczynek do wykonania oryginalnych wykresów CTPc° służących do analizy kinetyki przemian fazowych, zachodzących podczas odpuszczania tej stali uprzednio zahartowanej od wybranej temperatury austenityzowania.
EN
Results of preliminary research of a hot-work tool steel, grade 56NiCrMo7, are presented in this paper. The investigations have been focused on measurements of the steel’s critical temperatures and on microstructural analysis after softening annealing. The effect of austenitizing temperature on hardness and development of microstructure also was investigated. On the basis of the obtained results an original CHT (Continuous–Heating–Transformations) diagram will be developed, which can be used for analysis of phase transformations taking place during tempering of previously quenched steel.
11
Kinetyka przemian fazowych przy nagrzewaniu ze stanu zahartowanego stali 56NiCrMo7
Dąbrowski R., Dziurka R.
Hutnik, Wiadomości Hutnicze
|
2010
|
Vol. 77, nr 10
589-593
PL
W pracy przedstawiono oryginalny wykres CTPcO (czas – temperatura – przemiana) przy nagrzewaniu ciągłym ze stanu zahartowanego (odpuszczaniu), stali narzędziowej do pracy na gorąco w gatunku 56NiCrMo7. Wykres sporządzono dla wybranej temperatury austenityzowania równej 860 °C. Dla zilustrowania uzyskanych wyników zamieszczono dylatogram chłodzenia stali od 860 °C oraz dylatogramy nagrzewania ze stanu zahartowanego wraz z ich interpretacją. Na dylatogramach nagrzewania stwierdzono dwa wyraźne efekty dylatacyjne ujemne: pierwszy – pochodzący najprawdopodobniej od wydzielania węglika . oraz drugi – związany z wydzielaniem cementytu stopowego (M3C). Ponadto, zarejestrowano wyraźny efekt dylatacyjny dodatni związany z przemianą austenitu szczątkowego. Nie zaobserwowano natomiast efektu dylatacyjnego dodatniego pochodzącego od niezależnego zarodkowania węglików typu MC. Uzyskane wyniki badań pozwolą w przyszłości zmodyfikować technologię odpuszczania narzędzi wykonanych z badanej stali.
EN
In this paper the original CHT diagram (Continuous Heating Transformation) during heating from as-quenched state) of 56NiCrMo7 hot-work tool steel was presented. The diagram was prepared for the chosen austenitizing temperature 860 °C. To present the way of interpretation of the results, dilatograms of cooling the sample as well heating the samples from as-quenched state were studied. Two negative dilatationes effects were found on the dilatograms of heating: first – related most probably to the precipitations of ĺ carbide and second – related to the recipitations of alloyed cementite (M3C). Moreover, the positive dilatation effect related to the transformation of the retained austenite was registered. The positive dilatations effect related to cendependent nucleation of the carbides of MC type was not observed. Obtained results will let work out the detailed technology of tools tempering made of the investigated steel.
12
Content available remote The influence of laser modification on the structure and properties of the X40CrMoV5-1 and 32CrMoV12-28 hot work tool steels
Dobrzański L. A., Jonda E., Labisz K.
Archives of Materials Science and Engineering
|
2010
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Vol. 41, nr 2
104-111
EN
Purpose: The aim of this paper was to study the laser treatment technique and parameters, particularly the laser power, to achieve a high value of layer properties like hardness and microhardness 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 and technical conditions for remelting the surface layer with HPDL. Design/methodology/approach: This work presents the results of new laser treatment techniques applied in metal surface technology. There is presented laser treatment with remelting and/or alloying of X40CrMoV5-1 and 32CrMoV12-28 hot work tool steels with carbide powders as well as results of laser remelting influence on microstructure and properties of the surface, 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. Findings: The layer is 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.
13
Content available remote Structure and properties of the laser alloyed 32CrMoV12-28 with ceramic powder
Dobrzański L. A., Labisz K., Klimpel A.
Journal of Achievements in Materials and Manufacturing Engineering
|
2009
|
Vol. 32, nr 1
53-60
EN
Purpose: The work was performed for the reason to determine the laser treatment parameters, particularly 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 and technical conditions for remelting the surface layer with HPDL. Design/methodology/approach: The main methodology results of new laser treatment techniques applied in metal surface technology are presented and discussed. There is presented laser treatment with remelting of hot work tool steel 32CrMoV12-28 with ceramic powders especially carbide - TaC, 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: There was achieved a layer 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: There were four choused laser powers used and implicated by one process speed rate. Also one powder in form of TaC was used for alloying with the particle size of 10 ěm. 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.
14
Content available remote Surface modification of the X40CrMoV5-1 steel by laser alloying and PVD coatings deposition
Dobrzański L., Jonda E., Lukaszkowicz K., Labisz K., Klimpel A.
Journal of Achievements in Materials and Manufacturing Engineering
|
2008
|
Vol. 27, nr 2
179-182
EN
Purpose: The paper presents the influence of alloying with NbC powder by the use of a high-power diode laser and TiAlN, AlSiCrN and TiCN gradient coatings deposition by PVD process on microstructure and hardness of the X40CrMoV5-1 steel surface layer. Design/methodology/approach: Microstructure was characterised using optical metallography, scanning and transmission electron microscopy. Findings: In the effect of laser alloying with powders of carbide NbC occurs size reduction of microstructure as well as dispersion hardening through fused in but partially dissolved carbides and consolidation through enrichment of surface layer in alloying additions coming from dissolving carbides. The structure of the PVD coatings consisted of fine crystallites while their average size fitted within the range of 15-50 nm, depending on the coating type. The coatings demonstrated columnar structure. Research limitations/implications: It is necessary to continue the research to determine alloying parameters for demanded properties of hot work tool steels surface layers. Further investigations should be concentrated on the determination of the thermal fatigue resistance of the layers. Practical implications: Good properties of the PVD coatings and the laser treatment make these layers suitable for various technical and industrial applications. Originality/value: Laser alloying by using different carbide powders and HPDL laser is a new way to improve the structure and mechanical properties of the hot work tool steels.
15
Content available remote Laser treatment of the surface layer of 32CrMoV12-28 and X40CrMoV5-1 steels
Dobrzański L. A., Labisz K., Jonda E.
Journal of Achievements in Materials and Manufacturing Engineering
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2008
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Vol. 29, nr 1
63-70
EN
Purpose: 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 and X40CrMoV5-1 hot work steels, using the high power diode laser (HPDL). In this paper there are presented the investigation results of mechanical properties and microstructure with ceramic particle powders VC vanadium carbide and WC tungsten carbide. The purpose of this work was also to determine the laser treatment conditions for surface layer treatment of the investigated steels. Design/methodology/approach: The purpose of this work was the determination of technological conditions for alloying and remelting of the surface layer particularly the laser power. There is studying the influence of treatment on the remelting depth of the surface layer to achieve high layer hardness for protection of the steel and also make the surface more resistant for work. Findings: As a result structure changes in form of fragmentation were determined. For alloying the tungsten carbide and vanadium carbide powders were used. Two phases of carbides, VC and WC, were observed. Research limitations/implications: The remelted layers which were formed on the surface of the investigated hot work steel were examined metallographically and analyzed using a hardness and micro hardness testing, X-ray diffraction, EDS microanalysis, electron scanning microscope. Practical implications: This work helps to use the new developed laser treatment technique for alloying and remelting of hot work tool steel tools for hot working conditions. Originality/value: The originality of this work is based on applying of High Power Diode Laser for improvement of steel mechanical properties as well the thermal fatigue and wear resistance.
16
Content available remote Mechanical properties of the surface layer of the laser alloyed 32CrMoV12-28 steel
Dobrzański L., Labisz K., Piec M., Klimpel A.
Archives of Materials Science and Engineering
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2008
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Vol. 29, nr 1
57-60
EN
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.
17
Content available remote Modelling of surface layer of the 32CrMoV12-28 tool steel using HPDL laser for alloying with TiC powder
Dobrzański L. A., Labisz K., Piec M., Klimpel A.
Journal of Achievements in Materials and Manufacturing Engineering
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2007
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Vol. 24, nr 2
27-34
EN
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.
18
Content available remote Modelling of gradient layer properties of the 32CrMoV12-27 surface layer alloyed with WC powder
Dobrzański L. A., Labisz K., Klimpel A., Lelątko J.
Journal of Achievements in Materials and Manufacturing Engineering
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2007
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Vol. 20, nr 1-2
343-346
EN
Purpose: The reason of this work was to determine the thermal fatigue resistance, the laser treatment parameters, particularly 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 and technical conditions for remelting the surface layer with HPDL. Design/methodology/approach: In this paper the results of new laser treatment techniques applied in metal surface technology are presented and discussed. There is presented laser treatment with remelting of hot work tool steel 32CrMoV12-28 with ceramic powders especially carbide - WC, 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: The layer is 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: The results present only four choused laser powers by one process speed rate. Also one powder in form of WC was used for alloying with the particle size of 10 micrometres. Originality/value: The originality of this work is based on applying of High Power Diode Laser for improvement of steel mechanical properties.
19
Content available remote Improvement of the hot work tool steel surface layers properties using a high power diode laser
Dobrzański L. A., Piec M., Klimpel A.
Journal of Achievements in Materials and Manufacturing Engineering
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2007
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Vol. 21, nr 1
13-22
EN
Purpose: The purpose of this research paper is focused on the X38CrMoV5-3 hot work tool steel surface layers properties using HPDL laser. Design/methodology/approach: The aim of this research paper is to present deposition technologies, investigation of structure and properties of the X38CrMoV5-3 hot work tool steel alloying with ceramic particles using high power diode laser HPDL. Selection of laser operating conditions is discussed, as well as beam face quality after remelting, hardness, micro hardness test, wear resistant, EDX, TEM and X-ray microanalysis results. Findings: The structure of the solidified material after the laser remelting is characterized by the diversified morphology connected with the multiple changes of the crystal growth direction from little dendrites to tiny equiaxed grains in the near-surface zone. The main axes of the dendrites are directed according to the heat abstraction directions on the border of the solid and liquid phases with the carbides' clusters arranged according to the whirls caused by a convectional movement in the pool of the metallic liquid as well as partly unremelted conglomerates NbC, TaC, VC, WC and TiC as a melting material in the middle area of the remelted zone. Research limitations/implications: Laser technique features the especially promising tool for solving the contemporary surface engineering problems thanks to the physical properties of the laser, making it possible to focus precisely the delivered energy in the form of heat in the surface layer. Practical implications: Practical implications are: regeneration and manufacturing of various tools from the X38CrMoV5-3 hot-work tool steel. Originality/value: The laser treatment as a part of the new generation techniques applied in metal surface technology.
20
Content available remote Comparison of the thermal fatigue surface layers of the X40CrMoV5-1 hot work tool steels laser alloyed
Dobrzański L. A., Jonda E., Polok A., Klimpel A.
Journal of Achievements in Materials and Manufacturing Engineering
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2007
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Vol. 24, nr 2
135-138
EN
Purpose: The comparison of thermal fatigue and mechanical properties of the hot work tool steels alloyed with carbide powders has been presented. The effect of laser alloying with powders on the surface layers alloying with HPDL was evaluated. Design/methodology/approach: In this paper the result of laser surface alloying is discussed. The material used for investigation were hot work tool steels X40CrMoV5-1 and 55NiCrMoV7 alloyed with TiC or TaC using high power diode laser. Findings: The thermal fatigue resistance measured with the average cracks deep subjected to steel alloyed with TiC powder is few times smaller compared to the steel after a conventional heat treatment, which was used as a reference material. The hardness value increases according to the laser power used in alloying. Research limitations/implications: It is necessary to continue the research to determine alloying parameters for demanded properties of hot work tool steels surface layers. Practical implications: The proposed new methods of enhancement fatigue resistant of hot work tool steels was the aim goal of this work. Originality/value: Laser alloying by using different carbide powders and HPDL laser is a new way to improve the structure and mechanical properties of the hot work tool steels.
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