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1

The effect of the austenitisation temperature for the two-stage heat treatment of high-manganese steels on its wear resistance under abrasive conditions

Dziubek Mateusz, Rutkowska-Gorczyca Małgorzata, Grygier Dominika

Tribologia

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2023

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nr 3

19--29

EN

Fine-grained high-manganese X120Mn12 grade steel was subjected to a two-stage heat treatment consisting of long-term isothermal annealing at 510°C, which was followed by resaturation in order to reduce the negative effect of the brittle carbide carbides of manganese cementite (Fe,Mn)3 C. The objective of the experiment was to elucidate the effects of distinct stages of heat treatment on the properties of high manganese steel with regard to its resistance to abrasive wear. Supersaturation was performed for eleven different variations of temperature values ranging from 600°C to 1100°C to verify its effect on the resistance to abrasion wearunder abrasion conditions. An increase in the supersaturation temperature results in the gradual coagulation and disintegration of the colonies of pearlite and needle-like carbides (Fe,Mn)3 C formed during isothermal annealing. At the same time, as a result of the PSN (particle stimulated nucleation) process, the microstructure of austenite undergoes partial refinement, which ultimately increases the resistance to abrasive wear. As a result of the final microstructural changes resulted in an increase in the resistance to abrasion of approximately 6% compared to the initial state.

PL

Drobnoziarnistą stal wysokomanganową gatunku X120Mn12 poddano dwustopniowej obróbce cieplnej złożonej z długoterminowego izotermicznego wygrzewania w temperaturze 510°C, a następnie ponownemu przesycaniu w celu zredukowania negatywnego wpływu kruchych wydzieleń węglików cementytu manganowego (Fe,Mn)3 C. Eksperyment miał na celu poznanie wpływu poszczególnych etapów obróbki cieplnej na właściwości stali wysokomanganowej w kontekście odporności na zużycie ścierne. Etap przesycania zrealizowano dla jedenastu różnych wariantów wartości temperatury z zakresu od 600°C do 1100°C w celu zweryfikowania jej wpływu na odporność na zużycie ścierne. Wzrost temperatury przesycania skutkuje stopniową koagulacją oraz rozpadem powstałych w trakcie wyżarzania izotermicznego kolonii perlitu oraz iglastych węglików (Fe,Mn)3 C. Jednocześnie w wyniku procesu PSN (ang. particles stimulated nucleation) mikrostruktura austenitu ulega częściowemu rozdrobnieniu, co finalnie wpływa na wzrost odporności na zużycie ścierne. W wyniku końcowych zmian mikrostrukturalnych uzyskano wzrost odporności na ścieranie o około 6% w porównaniu do stanu wyjściowego dla wariantu obróbki cieplnej złożonego z etapu długoterminowego izotermicznego wyżarzania w temperaturze 510°C oraz następującego po nim przesycania w temperaturze 750°C. Wzrost odporności wywołany został wydzieleniem globularnych węglików (Fe,Mn)3 C oraz powstaniem nowych ziaren austenitu.

2

The correlation between microstructure, mechanical and tribological properties in the alloys of Co-Cr protectors with micro additives Mo and W

Augustyn-Nadzieja Joanna, Frocisz Łukasz, Matusiewicz Piotr

Tribologia

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2023

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nr 3

7--17

EN

The paper presents the results of tests of tribological wear of two Co-Cr-Mo alloys (Wironit LA) and Co-Cr-Mo-W (Colado CC) used to make skeletal prostheses, combined works, implants and metal frameworks for ceramics. The test samples were centrifugally cast using the lost wax method and subjected to hardness measurements, microscopic observations, and a quantitative description of the microstructure. SEM examinations and EDS analysis of micro-areas on dendritic arms and interdendritic areas were performed together. The abrasive wear resistance tests with the use of a T-05 tester in the friction system roller-block were conducted in a dry sliding contact under the conditions of a metal-metal contact with the load of 100 N and for two friction paths, 500 and 1000 m.

PL

W pracy przedstawiono wyniki badań zużycia tribologicznego dwóch stopów Co-Cr-Mo (Wironit LA) i Co-Cr-Mo-W (Colado CC) stosowanych do wykonywania protez szkieletowych, prac kombinowanych, implantów i szkieletów metalowych pod ceramikę. Badane próbki odlewano odśrodkowo metodą wosku traconego i poddawano pomiarom twardości, obserwacjom mikroskopowym wraz z ilościowym opisem mikrostruktury. Wykonano badania SEM wraz z analizą EDS mikroobszarów na ramionach dendrytycznych oraz obszarów interdendrytycznych. Badania odporności na zużycie ścierne z wykorzystaniem testera T-05 w układzie ciernym wałek–blok przeprowadzono w suchym styku ślizgowym w warunkach kontaktu metal–metal z obciążeniem 100 N i dla dwóch dróg tarcia, 500 i 1000 m.

3

The influence of carbide reinforcement on the properties of sintered aluminium alloy matrix composites

Szewczyk-Nykiel Aneta

Technical Transactions

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2023

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Vol. 120, iss. 1

art. no. e2023005

EN

Based on the commercial aluminium alloy powder blend (Alumix 431D) metal matrix composites reinforced with particles of SiC as well as TiC were produced by conventional powder metallurgy technology and the effect of the type and amounts of reinforced particles on the selected properties and microstructure of sintered composites were investigated. In particular, the densification behaviour, the wear resistance and the corrosion resistance in 3.5% NaCl solution were identified. It was stated that both the type and the weight fraction of carbide used as particulate reinforcement have a great impact on the properties of aluminium alloy matrix composites. It was shown that the introduction of titanium carbide has a more favourable effect on the properties of sintered Alumix 431D matrix composites in comparison to silicon carbide and the optimum content of TiC in composite is 4 wt. % due to the highest hardness, wear resistance (wear rate of 2.865·10 ̄ ³ mm³/m) and simultaneously the best corrosion resistance (corrosion rate of 0.005 mm/year).

4

Badanie właściwości mechanicznych stali S355JR o różnych typach budowy mikrostruktury

Lipiec Sebastian

Stal, Metale & Nowe Technologie

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2023

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nr 1-2

36--40

PL

W artykule analizowana jest stal S355JR o różnych typach budowy mikrostruktury: poddana normalizacji, ze strukturą ferrytyczno-perlityczną (FP), oraz po wygrzewaniu austenityzującym, następnie chłodzona z dużą prędkością poprzez hartowanie w oleju, ze strukturą ferrytyczno-bainityczną (FB).

XX

An important aspect in the engineering design process is to know the true material characteristics of steels used in specific microstructures. These steels, depending on, among other things, heat treatment or working conditions and regimes, are characterised by a different microstructure. It is important to know the levels of both strength, ductility and fracture toughness of steels with different microstructure. This paper presents the results of an experimental study of S355JR steel with two types of microstructure: ferritic-perlitic and ferritic-bainitic. The basic strength and ductility characteristics of the steel determined by uniaxial tensile test and the results of fracture toughness tests are presented.

5

Dynamic Behaviour of Selective Laser Melted 316L Steel : Mechanical Properties and Microstructure Changes

Białobrzewski Paweł, Sienkiewicz Judyta, Janiszewski Jacek, Kluczyński Janusz

Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa

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2023

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Vol. 14, Nr 2 (52)

51--72

EN

316L steel specimens with three different shear zones made by SLM (Selective Laser Melting) were subjected to dynamic tests using the Split Hopkinson Pressure Bar method. The effect of high-speed deformation on changes in microstructure was analyzed. In addition, the stress-strain relationship was determined from the SHPB results. To visualize the deformation process of the specimens during the tests, a camera with a high frame rate was used. It was shown that as the plastic deformation increases, the hardness of the material increases. Microstructural analysis of dynamically loaded areas revealed numerous defects. Twinning was found to be the main deformation mechanism. Large plastic deformation and many other microstructural changes such as shear bands, cracks and martensite nucleation were also observed.

PL

Próbki ze stali 316L z trzema różnymi strefami ścinania wykonane metodą SLM (Selective Laser Melting) poddano testom dynamicznym wykorzystując do tego metodę dzielonego pręta Hopkinsona (Split Hopkinson Pressure Bar). Przeanalizowano wpływ odkształceń o dużej szybkości na zmiany w mikrostrukturze. Ponadto na podstawie wyników badań SHPB wyznaczono zależność naprężenie- odkształcenie. W celu zobrazowania procesu odkształcania próbek podczas badań zastosowano kamerę o dużej częstości klatkowania. Wykazano, że wraz ze wzrostem odkształcenia plastycznego wzrasta twardość materiału. Analiza mikrostrukturalna obszarów obciążonych dynamicznie ujawniła liczne defekty. Stwierdzono, że głównym mechanizmem deformacji jest bliźniakowanie. Zaobserwowano również duże odkształcenia plastyczne i wiele innych zmian mikrostruktury, takich jak pasma ścinania, pęknięcia i zarodkowanie martenzytu.

6

Method of experimental study of the force-deformation characteristics of the Belleville spring of the stop assembly of a direct-flow gate valve

Hasanov Ilman I., Guliyev Agali A., Tanriverdiyev Yusif A.

Nafta-Gaz

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2023

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R. 79, nr 11

742--748

EN

The article presents research methods and appropriate equipment for conducting experiments, as well as the analysis of the results. Studies on the hardness of the microstructure, elastic deformation and parts and samples were carried out using hardness testers, microscopes PMT-3, MIM-8 and devices for measuring the “force-strain” characteristic. The results of the study wer used to establish the dependence of the elastic properties of Belleville springs on the heat treatment modes, while also determining the microstructure and layer depth using various research methods. Every work studying the elastic properties and measurement of the static compressive force of a spring at a given strain value has been studied theoretically. Depending on the operating conditions, disc springs can be installed singly or assembled into packages, forming an elastic element working under compression. The research materials will be used in the work to improve the tightness of straight-through valves and the durability of the shut-off assembly parts. The dependence of the spring compression force and its deformation on the geometrical parameters of the disc springs has been established. Comparison of experimental and theoretical dependences has been made. It has been established that the residual deformation of the Belleville spring after captivity has a negative effect on the tightness of the shut-off valve assembly. The influence of various technological processes and modes of thermal treatment of disc springs on their elastic properties has been studied. Practical recommendations for improving the technological process of thermal treatment of Belleville springs have been proposed. The tasks of further research and implementation of the obtained results have been determined. Search work has been carried out to improve the technology of hardening processing of parts of the shut-off unit (gate and seat) of direct-flow valves. The possibility of using accelerated nitrocarburizing in a triethanolamine medium with induction heating by high-frequency currents at a temperature range of 950°С for boriding and borochroming has been established. Samples were made from standard steel grades 40, 40Kh and 38Kh2MYuA, subjected to hardening by the considered methods, and a study was made of the hardness, depth and microstructure of the hardened layer. Research in this direction should be continued in order to study the tribological characteristics (friction coefficient and wear resistance) of hardened parts. Each operation of the spring manufacturing technology has been studied, and deviations that have a significant impact on the operation of the spring and the sealing of the shut-off valve assembly have been identified.

PL

Artykuł przedstawia metody badawcze i odpowiednie wyposażenie służące do przeprowadzania eksperymentów, a także analizę wyników. Badania przyprowadzono przy użyciu testerów twardości, mikroskopów PMT-3, MIM-8 oraz urządzeń do pomiaru charakterystyki “siła-odkształcenie”. Wyniki tych badań wykorzystano do ustalenia zależności właściwości elastycznych sprężyn Belleville od parametrów obróbki cieplnej, jednocześnie określając mikrostrukturę i głębokość warstwy za pomocą różnych metod badawczych. Każdy przypadek badania właściwości elastycznych i pomiaru statycznego siłowego odkształcenia sprężyny przy danej wartości odkształcenia był analizowany teoretycznie. W zależności od warunków pracy sprężyny tarczowe mogą być montowane pojedynczo lub w pakietach, tworząc element elastyczny podlegający ściskaniu. Materiały badawcze mogą zostać wykorzystane w pracach mających na celu poprawę szczelności zasuw oraz trwałości części zespołu zamykającego. Ustalono zależność między siłą kompresji sprężyny i jej odkształceniem a parametrami geometrycznymi sprężyn tarczowych. Dokonano porównania wyników eksperymentalnych i teoretycznych. Ustalono, że szczątkowe odkształcenie sprężyny Belleville po jej zamontowaniu ma negatywny wpływ na szczelność zespołu zaworu zamykającego. Zbadano wpływ różnych procesów technologicznych i trybów obróbki cieplnej sprężyn tarczowych na ich właściwości elastyczne. Zaproponowano praktyczne zalecenia w celu poprawy procesu technologicznego obróbki cieplnej sprężyn Belleville. Określono cele dalszych badań i sposób wdrożenia uzyskanych wyników. Przeprowadzono prace badawcze w celu poprawy technologii hartowania części zespołu zamykającego (zasuwy i gniazda) zasuw klinowych. Sprawdzono możliwość zastosowania przyspieszonego azotonawęglania w środowisku trietanoloaminy z indukcyjnym ogrzewaniem prądem o wysokiej częstotliwości w zakresie temperatury 950°C w procesie borowania i borochromowania. Wykonano próbki ze standardowych gatunków stali 40, 40Kh i 38Kh2MYuA, które poddano hartowaniu przy rozważanych metodach, przeprowadzono badanie twardości, głębokości i mikrostruktury warstwy hartowanej. Badania w tym kierunku powinny być kontynuowane w celu zbadania charakterystyk tribologicznych (współczynnika tarcia i odporności na zużycie) hartowanych części. Przeanalizowano każdą fazę technologii produkcji sprężyny i zidentyfikowano odchylenia, które mają znaczący wpływ na działanie sprężyny i uszczelnienie zespołu zaworu zamykającego.

7

Wpływ manganu i miedzi na mikrostrukturę i właściwości spiekanych stali zawierających 0,7% węgla

Sułowski Maciej, Dąbrowski Robert, Piecuch Patrycja

Inżynieria Materiałowa

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2023

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Vol. 44, nr 4

25--29

PL

Określono wpływ manganu i miedzi na mikrostrukturę i właściwości mechaniczne spiekanych stali zawierających 0,7% węgla. Mieszanki proszków przygotowano w mieszalniku Turbula, a następnie wytworzono z nich wypraski, które prasowano pod ciśnieniem 660 MPa. Spiekanie realizowano w temp. 1120°C przez 60 min w atmosferze o składzie: 95% N2-5% H2. Po spiekaniu połowę spieków zawierających Mn i/lub Cu poddano odpuszczaniu w temp. 200°C przez 60 min. Wykazano, że w mikrostrukturze badanych stali spiekanych dominującymi składnikami były ferryt oraz perlit. W stalach Fe-Mn-C oraz Fe-Mn-Cu-C sporadycznie występował również bainit. Ponadto stale Fe-Mn-Cu-C charakteryzowały się najlepszymi właściwościami wytrzymałościowymi przy najgorszych właściwościach plastycznych.

EN

The influence of manganese and copper on the microstructure and mechanical properties of sintered steels containing 0.7% carbon was determined. The powder mixtures were prepared in the Turbula mixer. Green compacts were pressed under a pressure of 660 MPa. Sintering was carried out at 1120°C for 60 min in an atmosphere containing 95% N2 and 5% H2 . In addition, after sintering, half of the sinters containing Mn and/or Cu were tempered at 200°C for 60 min. It was shown that in the microstructure of investigated sintered steels the main constituents were ferrite and pearlite. In Fe-Mn-C and Fe-Mn-Cu-C steels, bainite was also observed. Moreover, Fe-Mn-Cu-C steels were characterized by the highest strength properties with the lowest plastic properties.

8

Analiza wybranych własności mechanicznych i tribologicznych medycznego stopu Ti24Nb4Zr8Sn

Dąbrowski Robert, Sułowski Maciej

Inżynieria Materiałowa

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2023

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Vol. 44, nr 5

11--15

PL

W artykule zaprezentowano wyniki badań twardości, odporności na pękanie oraz odporności na zużycie ścierne stopu Ti24Nb4Zr8Sn po obróbce cieplnej, tj. przesycaniu z temp. 850°C i starzeniu w 350, 450 i 600°C. Wykazano, że w stanie przesyconym, gdy w mikrostrukturze jest obecna jedynie faza β, stop charakteryzuje się najmniejszą twardością i największą odpornością na pękanie. Zastosowanie zabiegu starzenia, skutkujące wydzielaniem fazy α z przesyconej fazy β, silnie zmniejsza jego odporność na pękanie. Badany stop wykazuje istotnie różną odporność na zużycie ścierne i różny współczynnik tarcia, zależnie od mikrostruktury i twardości. Minimalną wartość współczynnika tarcia odnotowano po starzeniu w temp. 450°C, w której dochodzi do wydzielania w mikrostrukturze fazy α o dużej dyspersji, tj. przy maksymalnej twardości stopu.

EN

The article presents the results of hardness, fracture toughness and abrasive wear resistance tests of the Ti24Nb4Zr8Sn alloy. These results were obtained after its heat treatment, i.e. solution from 850°C and aging at 350, 450 and 600°C. It has been shown that in the supersaturated state, when only the β phase is present in the microstructure, the alloy is characterized by the lowest hardness and the highest fracture toughness. The application of the aging treatment, resulting in the separation of the α phase from the supersaturated β phase, strongly reduces its fracture toughness. The tested alloy shows significantly different resistance to abrasive wear and a different friction coefficient, depending on the microstructure and hardness. The minimum value of the friction coefficient was noted after aging at 450°C, at which the α phase with high dispersion was precipitated in the microstructure, i.e. at the maximum hardness of the alloy.

9

Analiza metalograficzna przyczyn pękania rury w strefie zgrzewu liniowego podczas kształtowania

Tyrała Dorota, Pawłowski Bogdan

Inżynieria Materiałowa

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2023

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Vol. 44, nr 3

8--11

PL

Celem pracy było określenie przyczyny powstawania pęknięć w partii rur fi 48,3×2,7 mm (stal S355J2H) w obszarze zgrzewu liniowego w trakcie operacji zmniejszania średnicy z 48,3 mm do 38 mm. Część z tych pęknięć nie była widoczna podczas obserwacji makroskopowych, pęknięcia ujawniono dopiero podczas badań z wykorzystaniem mikroskopu świetlnego. W trakcie badań metalograficznych na zgładach nietrawionych nie stwierdzono występowania wad metalurgicznych mogących mieć wpływ na powstawanie i propagacje obserwowanych pęknięć. Badania na zgładach trawionych ujawniły natomiast, że wszystkie badane odcinki rur nie wykazywały mikrostruktury właściwej dla prawidłowo przeprowadzonego procesu zgrzewania prądami wysokiej częstotliwości. Przyczyną powstawania pęknięć wzdłuż linii zgrzewu był nieprawidłowy przebieg procesu zgrzewania, najprawdopodobniej zbyt niska temperatura tego procesu.

EN

The aim of the study was to determine the cause of cracking of pipes fi 48.3×2.7 mm (S355J2H steel) in the seam weld area during the operation of reducing the diameter of 48.3 mm to 38 mm. Some of these cracks were not visible during macroscopic observations, cracks were revealed only during examinations using a light microscope. During the metallographic tests on the non-etched specimens, no metallurgical defects that could affect the formation and propagation of the observed cracks were found. On the other hand, tests on etched specimens revealed that all the examined pipe sections did not show the microstructure appropriate for a proper high-frequency welding process. The reason for the formation of cracks along the weld line is the incorrect course of the HF welding process, most likely too low temperature of this process.

10

The role of the matrix in SiC reinforced composites

Madej Marcin, Leszczyńska-Madej Beata, Wąsik Anna, Kopeć-Surzyn Anna

Composites Theory and Practice

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2023

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R. 23, nr 1

30--36

EN

This article presents a comparison of the properties of composites based on aluminum or aluminum alloy (Al4Cu) rein- forced with silicon carbide SiCp. The main objective was to analyze the possibility of producing an Al + Cu alloy matrix by basic powder metallurgy methods and its influence on the final properties of the composite. The composites were produced by pressing and sintering, basic powder metallurgy techniques, in order to reduce the manufacturing costs. Sintering was carried out in nitrogen due to the favorable effect of this atmosphere on the sintering of aluminum-based materials. Silicon carbide SiC was used as the reinforcing phase. The study clearly showed that the use of a matrix made of a mixture of Al and Cu powders results in an almost twofold increase in hardness (from 32 to about 60 HB) and a more than twofold increase in flexural strength (from about 200 to more than 450 MPa). Observations of the microstructure confirmed the diffusion of copper into the aluminum and the facets of the Al2Cu phase.

11

Effect of production process parameters on densification, microstructure and selected properties of spark plasma sintered Al4Cu-xSiC composites

Madej Marcin, Leszczyńska-Madej Beata, Wąsik Anna, Kopeć-Surzyn Anna, Korban Patryk, Garbiec Dariusz

Composites Theory and Practice

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2023

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R. 23, nr 3

173--180

EN

The paper presents the results of a study on the microstructure and hardness measurements of Al4Cu-xSiC (x = 5, 10, 20 and 30 wt.%) composites produced by spark plasma sintering (SPS). The sintering process was carried out in an HP D 25/3 plasma sintering furnace in a vacuum atmosphere, with sintering temperatures of 580 and 600°C and a densification pressure of 50 MPa. The heating rate was 100°C/min and the isothermal holding time at the sintering temperature was 2.5 min. As a reference material, the AlCu matrix was sintered under the same conditions. As a result, composites with a near-full density of 96.5-99.5% were obtained. Microstructure studies were performed employing the techniques of light microscopy, scanning, and transmission electron microscopy, along with analysis of the chemical composition in microareas. The test results did not reveal remarkable differences in the microstructure of the investigated composites sintered at 580 and 600°C. The sinters have a fine-grained microstructure with a strengthening phase located at the grain boundaries; locally, pores are visible. Increasing the SiC content in the composites promotes the formation of agglomerates of these particles. It was proven that a higher sintering temperature has a positive effect on the hardness of the studied composites.

12

Influence of ageing on microstructure and mechanical properties of TP347HFG austenitic stainless steel

Golański Grzegorz, Purzyńska Hanna

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 2

art. no. e144607

EN

The paper presents the results of microstructural and mechanical investigation of long-term aged TP347HFG austenitic stainless steel. Ageing was performed at a time of up to 30 000 hours and the temperature of 600 and 650◦C. Ageing was proved to lead to the precipitation of secondary phase particles not only inside grains but also on the boundaries of grains and twins. The MX precipitates were observed inside the grains. However, M23C6 carbides and sigma phase precipitates were observed on grain boundaries. The changes in the microstructure of the examined steel translated into the mechanical properties, i.e. initially observed growth and then the decrease of yield strength and a gradual decrease in impact energy. The overageing process – a decrease in strength properties – was associated with the growth of the size of M23C6 carbides and the precipitation of the sigma phase. The reduction of impact energy in TP347HFG austenitic stainless steel was found to be associated with the precipitation of M23C6 carbides in the case of the 600◦C temperature, and the M23C6 carbides and sigma phase in the case of the 650◦C temperature. The rate of changes in the microstructure and mechanical properties depended on the ageing temperature.

13

Effect of spray distance on the microstructure and corrosion resistance of WC - based coatings sprayed by HVOF

Jonda Ewa, Łatka Leszek, Maciej Artur, Godzierz Marcin, Gołombek Klaudiusz, Radziszewski Andrzej

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 2

art. no. e144610

EN

Cermet coatings provide protection against aggressive operating environment of machine and device elements, such as corrosion, wear or high-temperature conditions. Currently WC-based cermet coatings are frequently used in the different industry branches. In this work, conventional WC-based powders (WC-Co and WC-Co-Cr) were sprayed with High Velocity Oxy Fuel (HVOF) onto AZ31 magnesium alloy with different spray distances (320 and 400 mm). The aim of the research was to investigate the effect of the spray distance on the microstructure of the coatings, phase composition and electrochemical corrosion resistance. Results revealed that higher spray distance results in greater porosity, 1.9% and 2.3% for 320 mm and 2.8% and 3.1% for 400 mm in case of WC-Co and WC-Co-Cr coatings, respectively. Also the influence has been observed for coatings microhardness, c.a. 1300 HV0.3 for shorter spray distance, whereas for longer one it was less than 1100 HV0.3. The corrosion resistance estimated in potentiodynamic polarization measurements was the best for WC-Co-Cr coating deposited from the shorter spray distance, corrosion current density was equal to 2.9 µA·cm-2 and polarization resistance was equal to 8424 Ω∙cm2.

14

Analiza wpływu parametrów napawania laserowego LMD na wybrane właściwości napoin wytworzonych z proszku HS6-5-2c na stali 1.4923

Chrzanowski Wojciech, Napadłek Wojciech, Bogdanowicz Zdzisław

Biuletyn Wojskowej Akademii Technicznej

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2023

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Vol. 72, nr 1

116--130

PL

W pracy zaprezentowano wyniki badań napoin wytworzonych technologią napawania laserowego LMd (Laser Metal Deposition) z zastosowaniem różnych parametrów wiązki laserowej. na powierzchni podłoży ze stali 1.4923 w kształcie prostopadłościanów wytworzono napoiny wielościegowe z proszków hs6-5-2c o różnym stopniu przykrycia. W ramach prób napawania laserowego wytworzono próbki, na których następnie przeprowadzono badania topografii powierzchni, obserwacje mikrostruktury oraz pomiary twardości w poszczególnych strefach warstwy wierzchniej podłoża, to jest w strefie napoiny, strefie wpływu ciepła (sWc) oraz w strefie materiału rodzimego. obserwacjęi analizę powierzchni napoin oraz mikrostruktury w przekroju poprzecznym próbek po napawaniu LMd zrealizowano z zastosowaniem mikroskopii optycznej ze światłowodową transmisją obrazu. pomiary twardości wykonano, używając twardościomierza Vickersa FLc-50a. na podstawie obserwacji mikroskopowych stwierdzono, że uzyskane napoiny mają regularny i powtarzalny kształt. Ponadto na powierzchniach wytworzonych napoin oraz w strefie wtopienia materiału napoiny z materiałem podłoża nie zauważono występowania wad procesowych. Twardość uzyskanych napoin wynosiła 500-700 hV0,1. Wytworzone na bazie proszku hs6-5-2c napoiny poddano badaniom odporności na erozję, które wykazały znacznie wyższą odporność na zużycie erozyjne (nawet ok. pięciokrotnie) w porównaniu z materiałem podłoża (stal 1.4923) bez napawania.

EN

This paper presents the results of testing surfacings produced by LMd (Laser Metal deposition) laser deposition technology for different laser beam parameters. on the surface layer of rectangular-shaped samples, made of 1.4923 steel, multiwall surfacing was produced from hs6-5-2c powder with different degrees of coverage. as a part of the laser deposition verification and testing, surface topography, microstructure and hardness tests were carried out in the deposition zone, heat affected zone, and the zone of the parent material. The surface of the surfacing and the microstructure in cross-section were observed on an optical microscope with fibre-optic image transmission. Hardness measurements were made in the cross-section of the sample using a Vickers FLc-50a hardness tester. Based on the observations, it was found that the obtained surfacings have a regular and repeatable shape. There were no welding defects on the surfaces of the produced surfacings and in the zone of fusion of the surfacing material with the substrate material. The hardness of the surfacings was obtained in the range of 500-700 hV0.1. The surfacings produced by LMd technology were subjected to erosion resistance tests, which showed significantly higher (about 5 times higher) resistance to erosion wear of the produced surface layers (surfacings based on hs6-5-2c powder) in comparison with the substrate material, i.e., steel 1.4923.

15

A review of process parameters in friction drilling on joining of steels

Selvaraj R.M., Hynes N.R.J.

Archives of Materials Science and Engineering

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2023

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Vol. 119, nr 1

12--20

EN

Purpose: Friction drilling is a unique way of creating holes in steel. In a solitary advance, a rotating conical tool is utilized to enter by penetrating as an opening on the surface of the sheet and making a bushing without making a chip. During this process, the heat produced by the frictional power linking the device and the sheet metal workpiece is used to pierce and make a bushing out of work. The goal of this novel hole-making process is to improve the bushing length in the thin-walled sheet metals by forming a bush and then combining thin sheet metals. The inconceivable utilizations of warm grating penetrating in a few modern areas will introduce another period of interfacing processes for different work materials in automobiles. Design/methodology/approach: Researchers have undergone numerous experiments based on the machining parameters, including spindle speed, feed rates, Friction Contact Ratio (FACR), tool angle, tool diameter, sheet thickness, and the output of the friction drilling, includes the bushing length, surface roughness, tool wear, hardness, thrust force, torque and microstructural evaluation. Findings: The crucial concerns that should be addressed and researched by researchers in the near future, such as determining the optimal machining parameters of such process and analysing, bushing length, microstructural impacts on the many aspects and their performance, are highlighted. Research limitations/implications: This research paper tends to examine the advancements in research on the friction drilling method and its applications, taking into account the benefits and limits of friction drilling. Practical implications: The present paper identifies the machining parameters and their contribution towards the output level of various materials like Stainless steel, Brass, aluminium, titanium, tempered steel and nickel-based compounds of different thickness. Originality/value: The machining parameters like spindle speeds, feed rate, tool angles, thrust force, Torque, surface roundness, bushing height, frictional heat and tool diameter are optimized in the friction drilling. The incorrect bushing is formed due to the high thrust force, and Low temperatures cause ductility and softening issues.

16

The Use of the XGBoost and Kriging Methods in the Prediction of the Microstructure of CGI Cast Iron

Sztangret Łukasz, Olejarczyk-Wożeńska Izabela, Regulski Krzysztof, Gumienny Grzegorz, Mrzygłód Barbara

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 4

22--33

EN

Compacted Graphite Iron (CGI) is a unique casting material characterized by its graphite form and extensive matrix contact surface. This type of cast iron has a tendency towards direct ferritization and possesses a complex set of intriguing properties. The use of data mining methods in modern foundry material development facilitates the achievement of improved product quality parameters. When designing a new product, it is always necessary to have a comprehensive understanding of the influence of alloying elements on the microstructure and consequently on the properties of the analyzed material. Empirical studies allow for a qualitative assessment of the above-mentioned relationships, but it is the use of intelligent computational techniques that allows for the construction of an approximate model of the microstructure and, consequently, precise predictions. The formulated prognostic model supports technological decisions during the casting design phase and is considered as the first step in the selection of the appropriate material type.

17

The Influence of the Casting Process on Shaping the Primary Structure of Mg-Li Alloys

Bednarczyk Iwona

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 4

137--144

EN

This paper presents the results of a study to determine the influence of casting parameters (cooling rate in the casting mould, casting temperature) on the primary structure of Mg-4%Li-1%Ca alloy ingots. The macro- and microstructure analysis of the Mg-4%Li-1%Ca alloy was performed using light and electron microscopy techniques. Microhardness measurements were made for the Mg-4%Li-1%Ca alloy and phase identification in the Mg-4%Li-1%Ca alloy was made using X-ray phase analysis.

18

The Influence of Pearlite Present in the Microstructure of GX120MnCr13 Cast Steel on Wear Resistance

Kalandyk Barbara, Zapała Renata, Sulima Iwona, Furmańczyk Piotr, Kasińska Justyna

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 4

145--156

EN

The article presents the results of metallographic and tribological tests on GX120MnCr13 cast steel that was previously subjected to heat treatment (including solution treatment from 1100°C and isothermal holding at 250, 400, and 600°C for 100 hours). The temperatures of the isothermal holding process were selected in order to reflect the possible working conditions of the cast elements that can be made of this cast steel. Wear tests were carried out under dry friction conditions using the ball-on-disc method using a ZrO2 ball as a counter-sample. The tests were carried out with a load of 5 N. The influence of the long-term isothermal holding process on the microstructure of the tested cast steel was analysed by light and scanning microscopy; however, abrasion marks were also examined using a confocal microscope. Based on the tests conducted, it was found that in the microstructures of the sample after solution treatment and samples that were held in isothermal C, the grain boundary areas were enriched in Mn and Cr compared to the areas inside the grains. Pearlite appearedcondition at 250 and 400 in the sample that was heated (or held in isothermal holding) at 600°C; its share reached 41.6%. The presence of pearlite in the austenitic matrix increased the hardness to 351.4 HV10. The hardness of the remaining tested samples was within a range of 221.8-229.1 HV10. Increasing the hardness of the tested cast steel directly resulted in a reduction in the degree of wear as well as the volume, area, and width of the abrasion marks. A microscopic analysis of the wear marks showed that the dominant process of the abrasive wear of the tested friction pair was the detachment and displacement of the tested material through the indentation as a result of the cyclical impact of the counter sample.

19

Parametric Optimization for Producing Semi-Solid A383 Alloy using Cooling Slope Casting Process

Rao M. S., Khandelwal Himandshu, Kumar M., Kumar A.

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 1

43--52

EN

Cooling slope casting is a simple technique to produce semi-solid feedstock with a non-dendritic structure. The cooling slope technique depends on various parameters like slope length, slope angle, pouring temperature etc, that has been investigated in the present study. This work presents an extensive study to comprehend the combined effect of slope angle, slope length, pouring temperature, on hardness and microstructure of A383 alloy. Response Surface Methodology was adopted for design of experiments with varying process parameters i.e. slope angle between 15o to 60o, slope length between 400 to 700 mm, and pouring temperature between 560 oC to 600 oC. The response factor hardness was analysed using ANOVA to understand the effect of input parameters and their interactions. The hardness was found to be increasing with increased slope length and pouring temperature; and decreased with slope angle. The empirical relation for response with parameters were established using the regression analysis and are incorporated in an optimization model. The optimum hardness with non-dendritic structure of A383 alloy was obtained at 27o slope angle, 596.5 mm slope length and 596 oC pouring temperature. The results were successfully verified by confirmation experiment, which shows around 2% deviation from the predicted hardness (87.11 BHN).

20

Microstructure and Properties of Experimental Mg-9Al-5RE-1Zn-Mn Magnesium Alloy

Braszczyńska-Malik Katarzyna

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 4

169--172

EN

In this paper, an experimental Mg-Al-RE-type magnesium alloy, named AEZ951, is presented. The chemical composition of the investigated alloy was ca. 9 wt% Al, 5 wt% RE (rare earth elements), 0.7 wt% Zn and 3 wt% Mn. The experimental material was gravity cast into a cold steel mould. Microstructure analyses were carried out by light microscopy, along with X-ray phase analysis and scanning electron microscopy with an energy-dispersive X-ray spectrometer (SEM + EDX). Detailed investigations disclosed the presence of and Al10RE2Mn7 intermetallic compounds in the alloy microstructure. The(Mg) solid solution and Al11RE3, primary dendrites of an eutectic was also presented. The hardness, impact strength, tensile strength as well as the+volume fraction of the Al11RE3 phase and yield strength of the alloy were examined in tests at room temperature. The examined experimental Mg-Al-RE-type magnesium alloy exhibited higher mechanical properties than the commercial AZ91 alloy (cast in the same conditions).