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1

Evaluation of selected steel thermochemical treatment technologies using foresight methods

Dobrzańska-Danikiewicz A. D., Hajduczek E., Polok-Rubiniec M., Przybył M., Adamaszek K.

Journal of Achievements in Materials and Manufacturing Engineering

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2011

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Vol. 46, nr 2

115--146

EN

Purpose: The purpose of this article is to evaluate the development efficiency of classical steel thermochemical treatment. The criterion assumed for dividing the technologies into groups was the thermochemical treatment kind. Three technology groups were selected to realised researches, as follows: nitriding, carburising and diffusion boriding. Design/methodology/approach: In the framework of foresight-materials science researches: a group of matrices characterising technology strategic position was created, materials science experiments using: light microscope, transmission and scanning electron microscopes, X-ray diffractometer, microhardness tester, work-stands for testing of thermal fatigue resistance and mechanical fatigue strength, abrasion and corrosion resistance were conducted and technology roadmaps were prepared. Findings: The outcarried researches pointed out the great industrial importance of nitriding and carburising and good perspectives for these technology groups. However, diffusion boriding is obsolete and will slowly leave the market. Research limitations/implications: Researches concerning steel thermochemical treatment constitute a part of a larger research project aimed at identifying, researching, and characterizing the priority innovative technologies in the field of materials surface engineering. Practical implications: Nitriding and carburising with their popularity and good quality-price relation can be recommended for use in small and medium enterprises. Obsolete diffusion boriding is not recommended for that. Originality/value: The value of this paper is to evaluate the value of thermochemical treatment technologies in the background environment with their future development perspectives determination including the influence of thermochemical treatment on the quality, microstructure and properties of surface layers obtained by thermochemical treatment.

2

Effect of laser treatment on micro-structure and properties of cast magnesium alloys

Dobrzański L. A., Domagała-Dubiel J., Labisz K., Hajduczek E., Klimpel A.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 37, nr 1

57-64

EN

Purpose: The goal of this paper is to present the structure and properties of the cast magnesium alloy after laser treatment. Design/methodology/approach: The laser treatment of magnesium alloys with TiC, WC powders was carried out using a high power diode laser (HDPL). The resulting microstructure in the modified surface layer was examined using optical microscopy, scanning electron microscopy and transmission electron microscope. Phase composition was determined by the X-ray diffraction method using the XPert device. The measurements of hardness and wear resistance of the modified surface layer were also studied. Findings: The region after laser treatment has a fine microstructure with hard carbide particles. Hardness of laser surface layer with both TiC and WC particles was improved as compared to alloy without laser treatment. Research limitations/implications: In this research two powders (WC and TiC) were used with the particle size over 5 ěm. This investigation presents different laser power by one process speed rates. Practical implications: The results obtained in this investigation were promising towards compared other conventional processes. High Power Diode Laser can be used as an economical substitute of Nd:YAG and CO2 to improve the surface magnesium alloy by feeding the carbide particles. Originality/value: The originality of this work is applying of High Power Diode Laser for alloying of magnesium alloy using hard particles like tungsten and titanium carbides.

3

Structure and properties of laser alloyed gradient surface layers of the hot-work tool steels

Dobrzański L., Bonek M., Hajduczek E., Labisz K., Piec M., Jonda E., Polok A.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 31, nr 2

148-169

EN

Purpose: The purpose of this research paper is focused on the 55NiCrMoV7, 32CrMoV12-28, X40CrMoV5-1, X38CrMoV5-3 hot work tool steels surface layers improvement properties using HPDL laser. The paper present laser surface technologies, investigation of structure and properties of the hot work tool steels alloying with ceramic particles using high power diode laser HPDL. Design/methodology/approach: Investigation indicate the influence of the alloying carbides on the structure and properties of the surface layer of investigated steel depending on the kind of alloying carbides and power implemented laser (HPDL). Laser alloying of surface layer of investigated steel without introducing alloying additions into liquid molten metal pool, in the whole range of used laser power, causes size reduction of dendritic microstructure with the direction of crystallization consistent with the direction of heat carrying away from the zone of impact of laser beam. Findings: In the effect of laser alloying with powders of carbides NbC, TaC, TiC, WC and VC 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. Introduced particles of carbides and in part remain undissolved, creating conglomerates being a result of fusion of undissolved powder grains into molten metal base. In effect of convection movements of material in the liquid state, conglomerates of carbides arrange themselves in the characteristic of swirl. Remelting of the steel without introducing into liquid molten pool the alloying additions in the form of carbide powders, causes slight increase of properties of surface layer of investigated steel in comparison to its analogical properties obtained through conventional heat treatment, depending on the laser beam power implemented for remelting. Practical implications: 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 increase of hardness of surface layer obtained throughout remelting and alloying with carbides by high power diode laser is accompanied by increase of tribological properties, when comparing to the steel processed with conventional heat treatment. Originality/value: The outcome of the research is an investigation and proving the structural mechanisms accompanying laser remelting and alloying. The artificial neural networks were used to determine the effect of the technological effect of laser alloying on hardness and resistance wear abrasion of the hot work tool steels.

4

Crystallisation mechanism of laser alloyed gradient layer on tool steel

Bonek M., Dobrzański L. A., Piec M., Hajduczek E., Klimpel A.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 20, nr 1-2

411-414

EN

Purpose: The objective of the present work was to study the modification of the microstructure of hot-work tool steel X40CrMoV5-1 during the surface modifying by means of laser technology. Design/methodology/approach: The structural mechanism of surface layer development was determined and the effect of alloying parameters and thickness of paste layer applied onto the steel surface on structure refinement and influence of these factors on the crystallisation mechanism of surface layer was studied. Findings: development of the surface layer was observed in which one can distinguish the remelted zone, heat-affected zone and the transient zone. The finite 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 X40CrMoV5-1 conventionally heat treated steel was used as reference material. Practical implications: Laser surface modification 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. Originality/value: The outcome of the research is an investigation showing the structural mechanisms accompanying laser alloying.

5

Comparison of the secondary hardness effect after tempering of the hot-work tool steels

Mazurkiewicz J., Dobrzański L. A., Hajduczek E.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 24, nr 2

119-122

EN

Purpose: of this paper was to examine of the secondary hardness effect after tempering of the developed complex hot-work tool steel 47CrMoWVTiCeZr16-26-8 in relation to standard hot-work tool steel X40CrMoV5-1. Design/methodology/approach: The investigations steels were made using the specimens made from the experimental steel, for which the working 47CrMoW-V-TiCe-Zr16-26-8 denotation was adopted, similar to the ones used in the ISO Standard on using the standard alloy hot-work tool steel X40CrMoV5-1. Both investigated steels were melted in a vacuum electric furnace. Specimens made from the investigated steels were heat treated with austenitizing in salt bath furnaces for 30 minutes in the temperature range of 970-1180 degrees centigrade with gradation of 30 degrees centigrade. Next, the specimens were tempered twice in the temperature range of 450-660 degrees centigrade for 2 hours. Findings: The secondary hardness effect after tempering from temperature of 540 degrees centigrade in the 47CrMoW-V-Ti-CeZr16-26-8 steel and from temperature of 510 degrees centigrade for the X40CrMoV5-1 steel, which is caused by the carbides M4C3 and M7C3 in the 47CrMoWVTiCeZr16-26-8 steel and M7C3 in the X40CrMoV5-1 steel. Practical implications: The developed complex hot-work tool steel 47CrMoWVTiCeZr16-26-8 can be used to the hot work small-size tools which requires higher strength properties at elevated temperature. Originality/value: The obtained results show the influence of the chemical compositions on the secondary hardness effect after tempering in the hot-work tool steel. The secondary hardness effect after tempering determined structure and mechanical properties in this kinds of steels group.

6

Laser modification of surface layer properties of a hot-work tool steel

Bonek M., Dobrzański L. A., Hajduczek E., Klimpel A.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 14, nr 1-2

152--156

EN

Purpose: The objective of the present work was to study the modification of the microstructure of hot-work tool steel X40CrMoV5-1 during the surface modifying by means of laser technology. Design/methodology/approach: The initial experiments consisting in alloying the hot work tool steel indicate to the clear influence of the laser power on the run face shape and its depth. Findings: The structure of material solidifying after laser remelting is characteristic of the diversified morphology connected with the repeated changes of the crystals’ growth direction, from the small dendrites, whose principal axes are oriented in accordance with the heat removal direction sat the boundary between the solid and liquid phases, clusters of carbides arranged in accordance with the swirls caused by the metallic liquid convection motion, and partially non-remelted WC conglomerates as the alloying material in the central area of the remelted zone, to the fine equiaxial grains in the subsurface zone. Research limitations/implications: Laser remelting and alloying with the tungsten carbide results in refinement of the structure in the entire laser power range and in diversification of the grain size in the particular surface layer zones. Practical implications: Laser alloying 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. Originality/value: 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.

7

Influence of the Zr and Ce on the structure of experimental hot-work tool steel

Dobrzański L. A., Mazurkiewicz J., Hajduczek E.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 17, nr 1-2

49--52

EN

Purpose: of this paper was to examine of the influence of the Zr i Ce on the structure of the newly developed complex hot-work tool steel 47CrMoWVTiCeZr16-26-8 in relation to standard hot-work tool steel X40CrMoV5-1. Design/methodology/approach: The investigations steels were made using the specimens made from the experimental steel, for which the working 47CrMoWVTiCeZr16-26-8 denotation was adopted, similar to the ones used in the ISO Standard on using the standard alloy hot-work tool steel X40CrMoV5-1. Both investigated steels were melted in a vacuum electric furnace. Specimens made from the investigated steels were heat treated with austenitizing in salt bath furnaces for 30 minutes in the temperature range of 970-1180°C with gradation of 30°C. Next, the specimens were tempered twice in the temperature range of 450-660°C for 2 hours. Findings: The 47CrMoWVTiCeZr16-26-8 steel quenched from the temperature of 1120°C has the martensitic structure with the small portion of the retained austenite and alloy carbides partially dissolved during austenitizing (about 3.5%), including the MC type carbides (based on ZrC, TiC, (Ti,V)C and VC, with differing chemical compositions and crystallographic lattice parameter) and of the M2C3 type (based on Ce2C3). Research limitations/implications: Basing on the investigations of the newly developed 47CrMoWVTiCeZr16-26-8 steel and the standard X40CrMoV5-1 steel, the most advantageous heat treatment conditions were determined to obtain thesis most advantageous structure and mechanical properties: for the 47CrMoWVTiCeZr16-26-8 steel quenching at the temperature of 1120°C and tempering at the temperature of 540°C, and for the X40CrMoV5-1 one quenching at the temperature of 1060°C and tempering at the temperature of 510°C. Originality/value: The newly developed hot-work tool steel include Zr and Ce characterizations good structure and can be used to hot work small-size tools which requires higher strength properties at elevated temperature.

8

Mechanizm tworzenia laserowo modyfikowanej warstwy wierzchniej stali narzędziowej

Hajduczek E., Bonek M., Dobrzański L. A.

Inżynieria Materiałowa

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2006

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Vol. 27, nr 3

346-351

PL

Badania obejmują stopowanie węglikiem wolframu warstwy wierzchniej stali narzędziowej stopowej do pracy na gorąco X40CrMoV5-1 z zastosowaniem lasera diodowego dużej mocy (HPDL). Określono mechanizm strukturalny powstawania warstw wierzchnich, wpływ parametrów stopowania, sposobu ochrony gazowej i grubości powłok pasty naniesionej na powierzchnię stali na rozdrobnienie struktury oraz wpływ tych czynników na własności mechaniczne warstwy wierzchniej. Stwierdzono, że przetapianie i stopowanie laserowe węglikiem wolframu wpływa na rozdrobnienie struktury w całym badanym zakresie mocy lasera. W strefie przetopionej wielkość ziarna nie przekracza ok. 30 um2, gdy w materiale konwencjonalnie obrobionym cieplnie jest niemal dwudziestokrotnie większa. W strefie przetopionej i stopowanej występuje drobnokrystaliczna, dendrytyczna struktura o kierunku krystalizacji związanym z dynamicznym odprowadzaniem ciepła ze strefy oddziaływania wiązki lasera. Drobnokrystaliczna struktura martenzytu odpowiedzialna jest za wzrost twardości stopowanej warstwy. Rezultatem wykonywanych badań jest zbadanie i udowodnienie mechanizmów strukturalnych towarzyszących przetapianiu i stopowaniu laserowemu. Ma to ważne znaczenie poznawcze i daje podstawy do praktycznego wykorzystania tych technologii do kształtowania nowych narzędziowych funkcjonalnych materiałów gradientowych i regeneracji narzędzi już eksploatowanych.

EN

Investigations include comparison between structure and properties of remelting and alloying the X40CrMoV5-1 hot-work tool steel surface layer using the high power diode laser (HPDL). The tungsten carbide powder was used as an alloying material. The X40CrMoV5-1 conventionally heat treated steel was used as reference material. The structural mechanism was determined of surface layers development. The grain size is not more 30 um2 in the remelted zone, compared to the twenty times bigger grain size of the conventionally heat treated material. 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. It was found out that remelting and laser alloying with the tungsten carbide result in structure refinement in the entire investigated laser power range. The laser modified zone structure is characterized by the significant martensite dispersion with its lathes length several times shorter than of those developed during the conventional quenching. 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.

9

Charakterystyka warstwy wierzchniej stali narzędziowej stopowej X40CrMoV5-1 do pracy na gorąco stopowanej przy użyciu lasera diodowego dużej mocy

Bonek M., Dobrzański L.A., Hajduczek E., Klimpel A.

Mechanik

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2005

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R. 78, nr 4

344-351

PL

Opisano badania stopowania węglikiem wolframu warstwy wierzchniej stali narzędziowej stopowej do pracy na gorąco X40CrMoV5-1 z zastosowaniem lasera diodowego dużej mocy (HPDL). Określono mechanizm strukturalny powstawania warstwy wierzchniej oraz wpływ parametrów obróbki na strukturę i własności mechaniczne, a w szczególności na jej twardość, odporność na ścieranie oraz chropowatość.

EN

Described is research work on the tungsten carbide alloy case layer applied on hot work high speed X40CrMoV5-1 alloy steel tool surface with use of high power diode laser (HPDL).

10

Stal narzędziowa 47CrMoWVTiCeZrl6-26-8 do pracy na gorąco

Dobrzański L. A., Mazurkiewicz J., Hajduczek E.

Hutnik, Wiadomości Hutnicze

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2005

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Vol. 72, nr 3

182--187

PL

W pracy przedstawiono charakterystykę wieloskładnikowej stali 47CrMoWVTiCeZrl 6-26-8 przeznaczonej na narzędzia do pracy na gorąco. Stwierdzono, że badana stal po hartowaniu i odpuszczaniu ma strukturę martenzytu listwowego, częściowo zbliźniaczonego, z udziałem węglików stopowych typu MC i M 2 C 3 nierozpuszczonych w roztworze stałym, a także dyspersyjnych węglików typu M4C 3 oraz M7C3 odpowiedzialnych za efekt twardości wtórnej w czasie odpuszczania. Największe wartości wytrzymałości na rozciąganie, udarności i twardości uzyskuje badana stal po zahartowaniu z temperatury 1120°C i odpuszczaniu w 540 °C, natomiast maksymalną odporność na zmęczenie cieplne - po zahartowaniu i odpuszczaniu w 600 °C.

EN

The paperpresents characteristics ofthe multi-component hot-work tool steel ofthe 47CrMoWVTiCeZrl6-26-8 type. It has beenfound out that the investigated steel after ąuenching and tempering has the lath martensite structure, partially twinned, with alloy carbides ofthe MC andM2C3 type, undissohed in the solid solution, and also ofthe dispersive carbides ofthe M4C3 and M7C3 responsible for the secondary hardness effect during tempering. The highest values of the ultimate tensile strength, impact strength, and hardness are attained by the investigated steel after ąuenching at the temperaturę of 1120 °C and tempering at 540 °C, whereas the max,imum thermal fatigue resistance — after quenching and tempering at 600 °C.

11

Structure and properties of surface layers obtained by laser treatment of the hot-work tool steel

Dobrzański L.A., Bonek M., Hajduczek E., Klimpel A.

Inżynieria Materiałowa

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2004

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R. XXV, nr 3

564-567

EN

Investigations include alloying the X40CrMoV5-1 hot-work tool steel surface layer with the tungsten carbide, using the high power diode laser (HPDL). The structural mechanism was determined of surface layers development, effect was studied of alloying parameters, gas protection method, and thickness of paste layer applied onto the steel surface on structure refinement and influence of these factors on the mechanical properties of surface layer, and especially on its hardness, abrasive wear resistance, and roughness. Development of the surface layer was observed in which one can distinguish the remelted zone, whose thickness is 0,5 mm, heat-affected zone with thickness 0.8 mm, and the transient zone. It was found out that remelting and laser alloying with the tungsten carbide result in structure refinement in the entire investigated laser power range. 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. The dependence is presented of micro-hardness change on the laser beam effect on the treated surface, and especially the hardness increase in the alloyed layer. The X40CrMoV5-1 conventionally heat treated steel was used as reference material.

PL

Badania obejmują stopowanie węglikiem wolframu warstwy wierzchniej stali narzędziowej stopowej do pracy na X40CrMoV5-1 z zastosowaniem lasera diodowego dużej mocy (HPDL). Określono mechanizm strukturalny powstawania warstw wierzchnich, wpływ parametrów stopowania, sposobu ochrony gazowej i grubości powłok pasty naniesionej na powierzenię stali na rozdrobnienie struktury oraz wpływ tych czynników na własności mechaniczne warstwy wierzchniej, a w szczególności na jej twardość, odporność na ścieranie oraz chropowatość. W warstwie wierzchniej można wyodrębnić strefę przetopioną, której grubość nie przekracza ok. 0,5 mm, strefę wpływu ciepła o grubości do ok. 0,8 mm, oraz strefę przejściową. Stwierdzono, że stopowanie laserowe węglikiem wolframu wpływa na rozdrobnienie struktury w całym badanym zakresie mocy lasera. W strefie stopowanej występuje drobnokrystaliczna, dendrytyczna struktura o kierunku krystalizacji związanym z dynamicznym odprowadzaniem ciepła ze strefy oddziaływania wiązki lasera. Drobnokrystaliczna struktura martenzytu odpowiedzialna jest za wzrost twardości stopowanej warstwy. Przedstawiono zależność zmiany mikrotwardości od wpływu wiązki laserowej na obrabianą powierzchnię, a w szczególności wzrost twardości w stopowanej warstwie. Jako materiał odniesienia stosowano stal X40CrMoV5-1 po standardowej obróbce cieplnej.

12

Struktura i własności wieloskładnikowej stali do pracy na gorąco 47CrMoWVTiCeZr16-26-8 po obróbce cieplnej

Dobrzański L.A., Mazurkiewicz J., Hajduczek E.

Inżynieria Materiałowa

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2003

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R. XXIV, nr 6

283-286

PL

W pracy przedstawiono strukturę i własności nowo opracowanej wieloskładnikowej stali narzędziowej do pracy na gorąco 47CrMoWVTiCeZr16-26-8. Stwierdzono, że badana stal po hartowaniu i odpuszczaniu ma strukturę martenzytu listwowego, częściowo zbliźniaczonego, z udziałem węglików stopowych typu MC i M2C3 częściowo nierozpuszczonych w roztworze stałym, a także dyspersyjnych węglików typu M4C3 oraz M7C3 odpowiedzialnych za efekt twardości wtórnej w czasie odpuszczania. Wyniki badań własności mechanicznych, odporności na zmęczenie cieplne oraz badań strukturalnych odniesiono częściowo do znormalizowanej stali narzędziowej do pracy na gorąco X40CrMoV5-1. Zarówno temperatura austenityzowania jak i temperatura odpuszczania istotnie wpływają na strukturę i własności badanej stali. Najwyższe wartości wytrzymałości na rozciąganie, udarności i twardości uzyskuje badana stal po zahartowaniu z temperatury 1120 stopni Celsjusza i odpuszczaniu w 540 stopniach Celsjusza, natomiast maksymalną odporność na zmęczenie cieplne - po zahartowaniu i odpuszczaniu w 600 stopni Celsjusza.

EN

The paper presents structure and properties of the newly developed multicomponent hot work tool steel of the 47CrMoWVTiCeZr16-26-8 type. It has been found out that the 47CrMoWVTiCeZr16-26-8 steel after quenching and tempering has the lath martensite structure, partially twinned, with alloy carbides of the MC and M2C3 type, partially undissolved in the solid solution, and also of the dispersive carbides of the M4C3 and M7C3 responsible for the secondary hardness effect during tempering. Results of the tests of mechanical properties, thermal fatigue resistance, and structural examinations have been referred in part to the X40CrMoV5-1 standard hot work tool steel. Both austenitizing temperature and tempering temperature have a great on the influence to structure and properties of investigations steel. The highest values of the ultimate tensile strength, impact strength, and hardness are attained by the investigated steel after quenching from the temperature of 1120 degrees centigrade and tempering at 540 degrees centigrade, whereas the maximum thermal fatigue resistance - after quenching and tempering at 600 degrees centigrade.