Wyniki wyszukiwania - BazTech

1

Effects of thermo-chemical treatment and grinding process of external cylindrical surfaces on residual stresses in 13CrMo4-5 steel

Wójcik R., Sawicki J.

Journal of Achievements in Materials and Manufacturing Engineering

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2023

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Vol. 120, nr 1

10--21

EN

Purpose This paper presents a study aimed at determining the effect of the carburizing treatment process and the subsequent grinding process on the residual stresses occurring in ring-shaped specimens made of 13CrMo4-5 steel. Design/methodology/approach During the tests, vacuum carburizing was used, achieving an effective case depth ECD = 0.5 mm. Subsequently, the cylindrical outer surfaces of the samples were ground by conventional plunge grinding and with innovative kinematics using a test stand based on a conventional flat-surface grinding machine. As part of the study, microhardness and residual stresses were measured before and after grinding. Measurements were carried out to a depth of 1 mm. The main component of the stand is an original special device that allows the cylindrical specimen to be clamped. Then the angle between its axis of rotation and the axis of rotation of the grinding wheel is set with respect to the plane of the grinding machine’s magnetic table. In the described tests, the axis of rotation of the cylindrical specimen was deviated from its original position by 15° and set at an angle of 75° to the axis of rotation of the grinding wheel. The specimens were ground with a grinding wheel of noble electro-corundum marked 38A60K8V. In both kinematic cases of the grinding process, a machining allowance of 0.01 mm was removed. Findings Grinding using innovative kinematics did not cause any significant changes in the microhardness distribution, either for vacuum or conventional carburizing. In addition, residual stress measurements using the Dawidenkov-Sachs method showed that innovative grinding enables a more favourable distribution than those obtained after conventional plunge grinding. Research limitations/implications Further research will focus on, among others, selecting the angular settings of the workpiece axes relative to the grinding wheel axes depending on their dimensions. Grinding guidelines should include coverage ratio, infeed value, grinding time, and peripheral speeds. In addition, the plan for future research includes measuring the components of the grinding force and the geometric structure of the surface. Practical implications Grinding process is a crucial stage of steel treatment in almost every industrial branch. In sustainable manufacturing, it is extremely important to produce high-quality items while reducing the cost of manufacturing and taking care of the environment and workers’ health. Originality/value The proposed test stand, together with the authors’ device, makes it possible to conduct machining of the external surfaces of cylindrical workpieces on a flat surface grinder. In this case, the innovation of the grinding process consists of the non-parallel alignment of the cylindrical rotational axis of the specimen and the rotational axis of the grinding wheel with respect to the plane of the magnetic grinding table.

2

Low-pressure ferritic nitrocarburizing: a review

Taczała-Warga J., Pawęta S.

Archives of Materials Science and Engineering

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2023

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Vol. 119, nr 2

62--70

EN

Purpose: The purpose of this article was to present in a concise and organized way the available knowledge about ferritic nitrocarburizing in low-pressure. The authors aimed to indicate the research gap, and the whole article is a starting point for further research. Design/methodology/approach: The research method was the analysis of available literature, patent database and industry notes from manufacturers of modern furnaces. Findings: The ferritic nitrocarburizing process has many advantages in line with the market demand and the lack of solutions. The article summarizes the knowledge in the field of the ferritic nitrocarburizing process as a systematization of knowledge and a starting point for further research. Research limitations/implications: The information described in the article requires further laboratory research. Practical implications: The information collected by the authors was the basis for developing the technology discussed in the LIDER/3/0025/L-12/20/NCBR/2021 project. Originality/value: Research on this type of treatment will enable the development of technology and will meet the expectations and needs of the industry. It will also provide benefits in the form of a better understanding of the processes and the determination of the relationship between the parameters and the properties of the obtained surface layers.

3

Effect of grinding conditions of gears made of 20MnCr5 steel after single-piece flow heat treatment on the condition of the surface layer of the tooth working surface

Stachurski W., Janica J., Januszewicz B., Pawłowski W., Sawicki J.

Archives of Materials Science and Engineering

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2023

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Vol. 120, nr 2

60--69

EN

Purpose: The paper investigated the effect of selected processing conditions during gear grinding on the value and distribution of microhardness and residual stress formed in the technological surface layer of gears after thermochemical treatment (TCT) conducted by a continuous single-piece flow method. Design/methodology/approach: The gears were carburised with LPC at 920°C, then quenched in a 4D Quenching chamber at 7 bar and tempered at 190ºC for 3 hours. In the next step, the working surfaces of the gear teeth were ground by supplying grinding fluid (GF) to the grinding zone using the WET method and the MQL method with a minimum amount. Measurements were made on the distribution of microhardness and residual stress formed in the technological surface layer of gears after thermochemical treatment and after the grinding process. Findings: The results of the study showed the influence of workpiece speed vw and the method of delivery to the grinding zone GF on selected parameters describing the condition of the technological surface layer of the teeth of gears made of 20MnCr5 steel. The grinding process with a white aluminium oxide grinding wheel causes deterioration in the material's residual stress state. For each of the three analysed workpiece speeds vw, smaller changes in microhardness with respect to the microhardness of the material before grinding occur in the surface layer of samples ground with GF fed with the MQL method. Similarly, residual stress values are in the area of favourable compressive stresses. Research limitations/implications: Environmental considerations and the need to comply with increasingly stringent environmental protection and worker safety regulations are pushing researchers and entrepreneurs to completely eliminate or reduce the consumption of grinding fluids in the grinding process. Based on the research and analysis carried out in this study, it was concluded that applying minimum GF by the MQL method could be an alternative to the conventional WET method.Practical implications: In sustainable manufacturing, it is extremely important to produce high-quality items while reducing the cost of manufacturing and taking care of the environment and workers' health. This includes the manufacture of gears, a basic component used in gear transmissions in the automotive industry, for example. The research has established that it is possible to use the MQL method, which reduces the amount of GF used when grinding the working surfaces of gear teeth, as an alternative to the conventional WET method. Originality/value: The conducted research was the first to determine the most favourable conditions, in terms of the obtained residual stresses and microhardness, for grinding the working surface of gear teeth using the MQL method.

4

Wpływ obróbki kriogenicznej i cieplno-chemicznej na poprawę trwałości eksploatacyjnej matrycy prasy do wyciskania metodą KOBO

Gołębiewska-Kurzawska J., Wiśniewski K., Juszczyk B., Kulasa J., Marszowski K., Kalabis J.

Rudy i Metale Nieżelazne Recykling

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2018

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R. 63, nr 10

8--14

PL

Celem niniejszej pracy była analiza możliwości poprawy trwałości eksploatacyjnej matrycy prasy do wyciskania metodą KOBO poprzez łączne zastosowanie różnych wariantów zabiegów obróbki kriogenicznej i cieplno-chemicznej. W pracy analizowano i oceniono ich wpływ na poprawę twardości i zużycie tribologiczne materiału matryc w testach twardości, udarności i tribologicznych. Rozwiązania (warianty obróbcze) zostały przetestowane na matrycach w warunkach rzeczywistej pracy.

EN

The aim of the present study was to analyse the possibility of improving the exploitation durability of die for KOBO extrusion process by using a combination of cryogenic and thermo-chemical treatments. The study analyzed and evaluated their influence on the improvement of hardness and tribological wear of dies material. The solutions (machining variants) have been tested on the matrices in real-life conditions..

5

Complex Reagent Efficiency in Reduction of Copper from the Slags in Conditions of the Smelter & Refinery Plant - Głogów

Wołczyński W., Migas P., Bydałek A. W., Najman K., Senderowski C., Kwapisiński P.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 3

86--90

EN

The copper droplets contained in the post-processing liquid slag are subjected to the treatment by the complex reagent. The complex reagent has been recently elaborated and patented in frame of the Grant No. PBS3/A5/45/2015. In particular, the complex reagent is dedicated to the post-processing slags coming from the Smelter and Refinery Plant, Głogów, as a product of the direct-to-blister technology performed in the flash furnace. The recently patented complex reagent effectively assists not only in agglomeration, and coagulation but also in the deposition of the copper droplets at the bottom of crucible / furnace as well. The treatment of the post-processing slags by the complex reagent was performed in the BOLMET S.A. Company as in the industrial conditions which were similar to those usually applied in the KGHM – Polish Copper (Smelter and Refinery Plant, Głogów). The competition between buoyancy force and gravity is studied from the viewpoint of the required deposition of coagulated copper droplets. The applied complex reagent improves sufficiently the surface free energy of the copper droplets. In the result, the mechanical equilibrium between coagulated copper droplets and surrounding liquid slag is properly modified. Finally, sufficiently large copper droplets are subjected to a settlement on the crucible / furnace bottom according to the requirements.

6

Study on homogeneity and repeatability of single-piece flow carburizing system

Madej A., Brewka A., Wołowiec-Korecka E.

Journal of Achievements in Materials and Manufacturing Engineering

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2017

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Vol. 84, nr 2

68--75

EN

Purpose: The purpose of this paper was to determine the homogeneity and replicability of carburized layers obtained by a continuous single-piece flow method. Design/methodology/approach: A series of 100 gears was carburized under low pressure atmosphere using the single-piece flow method. The microstructures of the obtained carbon layers were investigated. Hardness penetration pattern and carbon concentration profiles were tested. Findings: The findings have shown the validity/correctness of the microstructures of the carburized layers obtained by the single-piece flow method. It has been proved that the carbon layer in every gear is uniform, what confirms that each element is affected by the same process conditions and the gears in the whole series can be precisely reproduced. Research limitations/implications: The short-pulse low-pressure carburizing technology needs further investigation to understand its all mechanisms fully. Practical implications: The single-piece flow method provides the uniform and reproducible carburized layers with the precision magnitude exceeding the abilities of currently used thermo-chemical furnaces. When applying the method it is possible to obtain a uniform carburized case in every single gear from the whole series of elements subjected to the process. Optimized configuration of process parameters and carbon-carrying mixture allows to meet the high expectations of a modern and future industry, what is most crucial in exploiting carburized steel gears. Originality/value: The applicability of the LPC single-piece flow method to a demanding mass production has been verified. The statistical validity of research results of the whole manufactured series of gears is being performed for the first time.

7

Tribologiczna kwalifikacja materiałów na węzły trące maszyn roboczych

Senatorski J., Tacikowski J., Korwin M., Mączyński P.

Inżynieria Powierzchni

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2017

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nr 3

32--37

PL

W artykule przedstawiono wyniki badań tribologicznych oraz badań metaloznawczych zarówno materiałów już stosowanych, jak i przewidzianych do pracy w węźle trącym elementu sprzęgającego ciężarówki. W badaniach przyjęto dwie akredytowane procedury badawcze. Na podstawie uzyskanych wyników wykazano, że użyte do produkcji wymienionych elementów materiały z warstwami dyfuzyjnymi mają większą przydatność w porównaniu ze stosowaną dotychczas ulepszoną stalą współpracującą z brązem.

EN

This article presents the results of tribological and physical metallurgy studies of materials applied and designed to work in a frictional junction of a truck coupling element. In this study two accredited investigation procedures have been adopted. The obtained investigation results have shown the suitability of the applied materials with diffusion layers for these elements, in comparison to the previously applied toughened steel cooperating with bronze.

8

Characterization of the Surface Layer of Mg Enriched with Al and Si by Thermochemical Treatment

Mola R., Stępień E., Cieślik M.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 4

195--199

EN

The modified surface layers of Mg enriched with Al and Si were fabricated by thermochemical treatment. The substrate material in contact with an Al + 20 wt.% Si powder mixture was heated to 445ºC for 40 or 60 min. The microstructure of the layers was examined by OM and SEM. The chemical composition of the layer and the distribution of elements were determined by energy dispersive X-ray spectroscopy (EDS). The experimental results show that the thickness of the layer is dependent on the heating time. A much thicker layer (1 mm) was obtained when the heating time was 60 min than when it was 40 min (600 μm). Both layers had a non-homogeneous structure. In the area closest to the Mg substrate, a thin zone of a solid solution of Al in Mg was detected. It was followed by a eutectic with Mg17Al12 and a solid solution of Al in Mg. The next zone was a eutectic with agglomerates of Mg2Si phase particles; this three-phase structure was the thickest. Finally, the area closest to the surface was characterized by dendrites of the Mg17Al12 phase. The microhardness of the modified layer increased to 121-236 HV as compared with 33-35 HV reported for the Mg substrate.

9

System of single-piece flow case hardening for high volume production

Wołowiec-Korecka E., Korecki M., Stachurski W., Zgórniak P., Sawicki J., Brewka A., Sut M., Bazel M.

Archives of Materials Science and Engineering

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2016

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Vol. 79, nr 1

37--44

EN

Purpose: Purpose of this paper is development of single-piece flow system to precision thermal treatment of parts of mechanical gear using a short-pulse low-pressure carburising technology (developed for a new large-chamber furnace). Design/methodology/approach: Sections of the article discuss the novel constructions of the device in which parts being carburised flow in a stream, as well as the low-pressure carburising experiment. Findings: The method has been found proper carburised layers on typical gear used in automotive industry. Research limitations/implications: The short-pulse low-pressure carburising technology needs further investigation to fully understand its all mechanisms. Practical implications: The device resulting from the experiment can be a fully robotised part of a production line which can be included in a system of automatic control of a production process. Originality/value: The device resulting from the experiment is only known solution on the world.

10

Badanie wpływu obróbki cieplnej i cieplno-chemicznej na kształtowanie się odporności na zużycie przez tarcie staliwa stopowego

Budzynowski T., Mazurkiewicz A., Ropelewski Z.

TTS Technika Transportu Szynowego

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2015

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R. 22, nr 12

1802--1804, CD

PL

W pracy przedstawiono wyniki badań dotyczących wpływu obróbki cieplnej i cieplno-chemicznej na kształtowanie się odporności na zużycie przez tarcie staliwa zawierającego chrom w granicach do 4 do 12 % oraz molibden i wanad. Obróbka cieplno-chemiczna dotyczyła azotowania w atmosferach regulowanych w atmosferze amoniaku i zdysocjowanego amoniaku w czasie 20 h w temperaturach 480 i 530 °C. Obróbka cieplna dotyczyła hartowania z temperatury 930 °C z chłodzeniem w oleju, z następnym niskim odpuszczaniem w temperaturze 220 °C. Badanie przebiegu zużycia zrealizowano zgodnie z normą PN–83/H–04302 „trzy wałeczki – stożek”.

EN

In the paper introduced the results of tests influence heat and heat-chemical treatment on the forming of resistance on abrasive wear and cast steels includes Cr, Mo, V. The heat-chemical treatment referring to nitriding in controlled atmospheres with ammonia and dissocia-tioned ammonia in the time 20 h, in temperature 480 i 530 °C. The heat treatment referring hardening from 930 °C with oil-cooled and sequence low-tempering in 220 °C. The testing of course of abrasive wear was realised with conformity of standard PN–83/H–04302 “three rollers – cone”

11

Badania mikrostrukturalne warstw wierzchnich po obróbce cieplno-chemicznej

Marchlewski P., Szczeblewski M., Wach P.

TTS Technika Transportu Szynowego

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2015

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R. 22, nr 12

1036--1040, CD

PL

Celem zastosowania i badania warstw azotowanych jest optymalizacji technologii wykonania wyrobów o zwiększonej wytrzymałości na zużycie cierne. W artykule przedstawiono przykłady obserwowanych, przy użyciu mikroskopu świetlnego, mikrostruktur warstw otrzymanych po procesach azotowania różnych gatunków stali. Opisano sposób oceny poprawności prowadzonych procesów obróbek cieplno-chemicznych. Przeprowadzono analizę wpływu zastosowanych parametrów obróbek cieplno-chemicznych w oparciu o obserwacje i pomiary wy-konane przy użyciu analizatora obrazu. Przedstawiono podstawowe zalety i możliwości stosowania analizy obrazu w zagadnieniach materiałoznawczych. Możliwości pomiarowe zaprezentowano na przykładzie oceny grubości warstw uzyskiwanych w procesach obróbek cieplno-chemicznych powierzchniowych takich jak na przykład azotowanie. Wykazano przy tym skuteczność badań wykonywanych w zakresie mikroskopii świetlnej do wykrywania wad w warstwach azotowanych.

EN

The article includes examples observed by optical microscopy structures of the layers after nitriding processes different steel grades. Also shown is the method of assessing the accuracy of machining processes carried out thermo-chemical, as well as comparing them with each other on the basis of parameters or measurements carried out through image analysis. Measurement capabilities presented in the examples for the evaluation of the thickness of films and coatings obtained through processes of surface heat treatments such as nitriding. Also shown is the use of light microscopy for detection of defects in the nitrided layers.

12

Mechanical strength and reliability of the porous materials used as adsorbents/catalysts and the new development trends

David E.

Archives of Materials Science and Engineering

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2015

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Vol. 73, nr 1

5--17

EN

Purpose: This paper aims to provide an understanding on some aspects of the porous material strength and reliability and to present future trends of the research on the mechanical properties of this solid porous materials. Design/methodology/approach: It shows that a multitest approach must be designed in order to measure the particle strength and then optimise the production process to enhance its strength. This approach combines measurements reproducing the different types of stress generated in the separation or catalytic process with an extensive characterisation of the physical and mechanical properties of the porous solid, such as hardness, fracture toughnes, brittle, crushing, attrition, etc. The methodology outlined here on alumina single particle or bulk goes beyond the common practice of evaluating mechanical strength based on a comparative study using a single-crushing test and a bulk-crushing test. Findings: Some recent developments on the basic mechanics of solid porous materials are shown. The main concepts presented are the brittle fracture which leads to the mechanical failure of the porous materials, the measurement and statistical properties of the strength data, the mechanical reliability of the porous material pellets, the mechanical properties of the adsorbent or catalyst packed beds, etc. The use and use limitations of inorganic binders for increasing the mechanical strength is discussed and the most binder systems are presented. Research limitations/implications: The scientific basis for the issues on the adsorbent/ catalyst mechanical properties calls yet for further elucidation and development. Practical implications: It is pointed out that porous materials used as adsorbents/ catalysts, with a high and uniform distributed mechanical strength are beneficial to industrial, energetic and environmental applications. Originality/value: A new route for improving mechanical strength of adsorbents/catalysts will become an unavoidable task not only for their manufacturing but also for to improve the efficiency of separation and catalysis processes

13

Gravity/buoyancy competition within coagulation of copper droplets in slag

Wołczyński W., Bydałek A. W.

Archives of Materials Science and Engineering

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2015

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Vol. 76, nr 1

35--45

EN

Purpose: A suspension of copper droplets in the slag coming from the direct-to-blister process was subjected to the treatment analogous to that usually applied to the electric arcfurnace process. In particular, recently patented by authors, complex reagent was applied and verified. Design/methodology/approach: The suspension was subjected to coagulation and solidification. Both processes were studied, independently. The suspension of droplets was treated not only by the recently patented complex reagent but by the CaO – industrial compound (in the amount of 5 %wt.) as well, to make comparison between both substances effectiveness. Findings: The observation was focused on the behavior of droplets to conclude whether the droplets are settled on the crucible bottom due to the effect of gravity or pushed to the liquid slag’s surface due to buoyancy force influence. In the case of the patented reagent application, the coagulation mainly was completed by the droplets’ settlement on the crucible bottom. The treatment performed with the use of the CaO – compound promoted the influence of buoyancy force. The coagulated copper droplets were pushed to the liquid slag’s surface. Research limitations/implications: Rest reagents known in the industry practice will be subjected to the analogous analysis in order to make further comparison with the effect of the patented chemical. Practical implications: Conclusion from the performed experiment made in the crucible (laboratory scale) allow to suggest how to improve not only the semi- or fully industrial directto-blister technology but the treatment of the slag in the electric arc-furnace as well.

14

Tribocorrosion resistant chromized layers produced on tool steel by means of the pack cementation process

Kasprzycka E., Bogdański B., Senatorski J.

Tribologia

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2014

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nr 3

91--96

EN

Chromized carbide layers produced on a tool carbon steel surface by means of pack cementation process were investigated. Studies were carried out of layer thicknesses, their morphology, chromium, carbon and iron concentration depth profiles in the diffusion zone of chromized layers. The tribocorrosion resistance of chromized layers was determined. To determine the tribological properties, an Amsler machine of the A135 type was used. The friction unit was disk and plate. Lubrication was provided with a 50% water solution of physiological salt with drip feed of 60 drops/min. High tribocorrosion resistance of the investigated chromized layers was indicated.

PL

W pracy omówiono wyniki badań dotyczących węglikowych warstw chromowanych na stali narzędziowej nanoszonych metodą proszkową. Przeprowadzono badania grubości warstw, ich morfologii, składu fazowego, twardości oraz rozkładów stężenia chromu, węgla i żelaza w strefie dyfuzyjnej. Określono odporność warstw chromowanych na zużycie tribologiczno- korozyjne. Dla określenia właściwości tribologicznych użyto urządzenia Amsler typu A 135. Badanie odporności na zużycie przez tarcie wykonano metodą krążek–płytka, stosując smarowanie 50% roztworem soli fizjologicznej podawanym kroplowo ze stałym wydatkiem 60 kropli/ min. Udowodniono bardzo dobrą odporność na zużycie tribologicznokorozyjne warstw chromowanych.

15

Effect of gas nitriding process on tribological properties of constructional steel

Senatorski J., Tacikowski J., Kasprzycka E., Bogdański B., Czarnecki K.

Tribologia

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2014

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nr 4

105--111

EN

The paper presents the results of examinations of the structure and tribological properties of nitrided layers produced on constructional steels with use of controlled gas nitriding. The nitriding layers structure, hardness, and tribological properties were determined. Tribological properties of the layers were performed by means of taper-three roll test. It has been proven that the application of the gas nitriding process to constructional steels significantly improved their resistance to friction wear.

PL

W pracy omówiono wyniki badań dotyczących właściwości tribologicznych warstw azotowanych wytwarzanych na stalach konstrukcyjnych 18HGT i 38HMJ w procesie regulowanego azotowania gazowego. Tribologiczne właściwości otrzymanych warstw oceniano z wykorzystaniem testu trzy wałeczki–stożek. Badania właściwości tribologicznych próbek ze stali 18HGT i 38HMJ z warstwami azotowanymi wykazały, że zastosowanie azotowania gazowego wpływa w sposób istotny na zwiększenie ich odporności na zużycie przez tarcie.

16

Wybrane aspekty obróbki cieplnej, cieplno-chemicznej i powierzchniowej narzędzi ze stali proszkowych

Czechowski K., Toboła D., Wrońska I., Rusek P.

Inżynieria Powierzchni

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2014

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nr 3

55--63

PL

Przedstawiono wybrane możliwości polepszania jakości narzędzi ze stali otrzymywanych na drodze metalurgii proszków (PM) za pomocą obróbki cieplnej, obróbki cieplno-chemicznej i obróbki powierzchniowej (PVD, nagniatanie itd.). Podano standardowe warunki obróbki cieplnej dla wybranych narzędzi wykonanych ze stali otrzymywanych na drodze metalurgii proszków. Przedstawiono przykładowe możliwości kształtowania jakości narzędzi za pomocą obróbki nagniataniem i cieplno-chemicznej. Omówiono zagadnienia wpływu gatunku materiału narzędzi i warunków jego o b róbki cieplnej oraz powierzchniowej na wybrane właściwości fizyczne i użytkowe narzędzi. Przedstawiono przykładowe wyniki badań wykonanych w Instytucie. Otrzymane rezultaty pozwalają m.in. na stwierdzenie, że właściwy dobór gatunku stali i odpowiednie określenie warunk ów obróbki cieplnej i obróbki powierzchni o wej lub specjalnej łączonej obróbki mechanicznej i cieplno chemicznej stali umożliwiają osiągnięcie wysokiej jakości narzędzi i podwyższenie ich produktywności.

EN

Some possibilities of improving the quality of tools of steels manufactured by powder metallurgy (PM) through heat treatment, thermo ch emical treatment and surface processing (PVD, burnishing etc.) are presented. Standard conditions of heat treatment are given for selected PM steel tools. Examples of improving the quality of tools by burnishing and thermo chemical treatment are pr e sented. The effects of tool material type, heat treatment and surface processing on some the physical and end use properties of the tools are considered. Typical experimental results o b tained in the Institute are presented. These results allow us to conclude, int er alia, that the proper selection of steel grades, heat treatment conditions and surface processing or special combined mechanical and thermo chemical treatments , make possible the achievement of tools of high quality and increased productivity.

17

Wpływ sposobu hartowania na wielkość odkształceń detali wykonanych ze stali 16MnCr5 nawęglanych niskociśnieniowo

Dybowski K., Kula P., Atraszkiewicz R., Januszewicz B., Rzepkowski A., Jakubowski K.

Inżynieria Materiałowa

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2014

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Vol. 35, nr 5

367--369

PL

W artykule przedstawiono porównanie wielkości naprężeń i odkształceń nawęglanej niskociśnieniowo stali 16MnCr5 hartowanej w gazie pod wysokim ciśnieniem (azot) i w oleju. Porównania dokonano na bazie detalu jakim było średniej wielkości koło zębate. Wykonano pomiary geometryczne bicia promieniowego na średnicy podziałowej koła przed i po obróbce cieplnej. Na podstawie tych wyników badań oceniono wpływ sposobu hartowania na stopień odkształcenia.

EN

Measurements of radial run-out on the wheel pitch circle before and after heat treatment were made.The review of the influence of the quenching method on the distortion level was elaborated on the base of the research data.

18

Wpływ obniżonego ciśnienia na kinetykę wzrostu warstw dyfuzyjnych w atmosferze chlorków chromu

Bogdański B.

Inżynieria Materiałowa

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2014

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Vol. 35, nr 5

358--360

PL

W pracy przedstawiono wyniki badań dotyczących chromowania dyfuzyjnego stali niskowęglowej, za pomocą metody proszkowej, zmodyfikowanej dla uniknięcia utleniania wsadu przez zastosowanie obniżonego ciśnienia podczas procesu,. Procesy chromowania prowadzono w atmosferze chlorków chromu, pod obniżonym ciśnieniem w zakresie od 1 do 800 hPa w temperaturze 850°C i 950°C. Przeprowadzono pomiary grubości warstw, określono ich skład fazowy i profile stężenia Cr, Fe i C w strefie dyfuzyjnej warstwy. Zbadano wpływ parametrów procesu, takich jak czas i temperatura, na kinetykę wzrostu warstw na stali węglowej. Wykazano, że chromowanie dyfuzyjne prowadzone w atmosferze chlorków chromu, pod obniżonym ciśnieniem, zmodyfikowaną metoda próżniową, jest bardziej efektywne z punktu widzenia kinetyki wzrostu warstwy niż chromowanie wykonywane tradycyjną metodą proszkową.

EN

Diffusion chromizing of low carbon steel has been investigated, using a powder method, modified by the use of low pressure during the process for the avoidance of the oxidation of the batch. Chromizing processes have been performed in chromium chlorides atmosphere at a low pressure range from 1 to 800 hPa, the treatment temperature 850°C and 950°C. Studies of the layers thickness, the phase composition, Cr, Fe and C depth profiles of concentration in diffusion zone have been conducted. The effect of the process parameters such as time and temperature on layer diffusion growth on the low carbon steel surface has been investigated. Chromizing conducted in chromium chloride atmosphere at low pressure, by means a novel vacuum method, was found to be most effective for maximizing the rate growth of diffusion layers than that for chromizing by pack cementation method.

19

Rola powłok ze stopów niklu w kształtowaniu właściwości warstw duplex wytwarzanych w procesie tytanowania próżniowego

Kasprzycka E.

Inżynieria Materiałowa

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2014

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Vol. 35, nr 5

378--381

PL

W pracy omówiono budowę i właściwości warstw duplex typu TiC+(Ni-W), otrzymywanych w procesie tytanowania próżniowego na powierzchni stali narzędziowej C90U pokrytej elektrolitycznie stopem niklu z pierwiastkiem węglikotwórczym – wolframem. Przeprowadzono porównanie warstw duplex typu TiC+(Ni-W) z warstwami duplex typu TiC+Ni otrzymywanymi na powierzchni stali pokrytej czystym niklem oraz z pojedynczymi warstwami węglikowymi typu TiC. Wykonano pomiary grubości warstw, zbadano ich morfologię oraz wyznaczono profile stężeń pierwiastków w strefie dyfuzyjnej tych warstw. Właściwości tribologiczne warstw określono metodą trzy wałeczki – stożek. Wykazano, że odporność na zużycie przez tarcie warstw duplex typu TiC+(Ni-W), otrzymywanych w procesie tytanowania próżniowego na powierzchni stali pokrytej stopem niklu Ni-W zawierającym pierwiastek węglikotwórczy-wolfram, jest równie dobra jak warstw węglikowych typu TiC wytwarzanych bez powłoki elektrolitycznej. Stwierdzono bardzo dobrą odporność na zużycie przez tarcie tych warstw, podczas gdy właściwości tribologiczne warstw duplex typu TiC+Ni oraz próbek ze stali bez warstw nie były dobre.

EN

The paper presents the results of examinations of the microstructure and properties of TiC+(Ni-W) duplex layers, produced by means of vacuum titanizing, on C90U tool steel surface covered electrolytically with Ni-W nickel alloy, containing carbide-forming element – wolfram. A comparison of the TiC+(Ni-W) duplex layers with the TiC+Ni duplex layers, produced on steel surface covered with pure nickel, and the TiC type single carbide layers has been performed. Studies of layers thickness, their morphology, concentration depth profiles of elements in diffusion zone of these layers have been carried out. Tribological properties of the layers were performed by means of taper-three rolls test. It has been proved, that the wear resistance by friction of the TiC+(Ni-W) type duplex layers, produced in vacuum titanizing of steel covered with Ni-W nickel alloy containing carbide-forming element – wolfram, is such good as carbides layers of the TiC type, produced on the steel surface without electrolytic coating. The high wear resistance of these layers has been proved, whereas tribological properties of the TiC+Ni duplex layers and the steel samples without any layers were not good.

20

Forming properties of titanium alloy for biomedical applications

Klimas J., Łukaszewicz A., Szota M., Bukowska A., Nabiałek M.

Archives of Materials Science and Engineering

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2014

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Vol. 70, nr 2

61--69

EN

Purpose: A preparation of surface layers on the surface of the titanium alloy Ti-6Al-4V as a result of thermo-chemical treatment and a comparison of obtained layers from baseline. The results of studies comparing the structure and properties of titanium alloy Ti-6Al-4V with produced surface layers. Design/methodology/approach: Test samples were the titanium alloy Ti-6Al-4V, which was subjected to heat-chemical treatment, consisting in annealing components in air for 1 hour at each temperature: 400ºC, 450ºC, 500ºC, 550ºC, 600ºC. To achieve pursued objective the following tests: microstructural observation of the cross section, which made it possible to study the thickness of the produced coating study were performed, a study of the geometry of the surface was performed – roughness and hardness were measured. Wear resistance of each layer was shown. Ringer liquid simulates the conditions similar in the human body. Results: Through the use of thermo-chemical treatment, it is possible to obtain surface layers of different thicknesses on titanium alloy Ti-6Al-4V. A method used for thermo-chemical treatment can produce a layer that affect the increase in hardness, whose value is almost twice higher than that of the without workup alloy. The evaluation of surface topography allowed to state that all samples were subjected to thermal-chemical treatment have a similar level of the development of the surface. The lowest roughness has alloy, annealed at 500°C. The study shows that the corrosion resistance of titanium alloy is dependent on the thickness of the obtained surface layers. The highest corrosion potential has the sample annealed at 500°C. Originality/value: The paper summarizes comparative studies of titanium alloy and the alloy with produced oxide layers, proving by far superior to the results with produced alloy layers, which one were produced by the injection method, than in the case of alloys produced by the drawing method.