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1

Comparative Study of Metal-Mineral Abrasive Wear Resistance of Hardfacing Layers Produced Through Different Methods

Leszek Łatka, Karolina Płatek, Mirosław Szala, Piotr Koruba, Paweł Sokołowski, Jacek Reiner

Tribologia

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2024

|

nr 1

89--98

EN

This article presents a comparison of the results of metal-mineral abrasion resistance investigations of hardfacing layers produced through different welding methods: (i) arc, (ii) plasma, and (iii) laser. Flux-cored wire with a metallic core (SK600-G) was used as a feedstock material. The work investigated the influence of basic hardfacing parameters on the geometry, microstructure, and correctness of making single beads . Then, full layers were made with the parameters selected for each method and abrasion resistance tests were carried out in accordance with the ASTM G65 standard. The obtained test results were analyzed for mechanical properties and microstructure of the produced padding welds. On the basis of the tests and analysis of the results, it was found that the use of methods with high energy density has a positive effect on the reduction in the coefficient of the share of the base material in the padding weld, while increasing the hardness. Comparative analysis of the resistance to metal-mineral abrasive wear showed that the resistance was approx. 25% higher for plasma layers and approx. 35% for laser layers, compared to electric arc-deposited layers.

PL

W artykule przedstawiono porównanie odporności na zużycie ścierne typu metal–minerał warstw napawanych różnymi metodami spawalniczymi: (i) łukowo, (ii) plazmowo oraz (iii) laserowo. Jako materiał dodatkowy zastosowano drut proszkowy z rdzeniem metalicznym (SK600-G). W pracy badano wpływ podstawowych parametrów napawania na geometrię, mikrostrukturę oraz poprawność wykonania pojedynczych ściegów. Następnie wykonano pełne warstwy wybranymi parametrami dla każdej z metod i przeprowadzono badania odporności na zużycie ścierne, zgodnie z normą ASTM G65. Uzyskane wyniki badań analizowano w kontekście własności mechanicznych oraz budowy mikrostrukturalnej wytworzonych napoin. Na podstawie analiz wyników badań stwierdzono, że zastosowanie metod o wysokiej gęstości energii korzystnie wpływa na redukcję współczynnika udziału materiału podłoża w napoinie, przy jednoczesnym wzroście twardości. Porównując odporność na zużycie ścierne typu metal–minerał zaobserwowano zmniejszone zużycie o ok. 25% dla napoin plazmowych oraz o ok. 35% dla napoin laserowych w porównaniu do napoin wykonanych metodą łukową.

2

The Influence of the Hot Working Tool Steel Substrate Material on the Element Distribution, Microstructure and Hardness of Gas Metal Arc Welding Hardfaced Layers

Lachowicz Marzena M., Sokołowski Paweł, Kaszuba Marcin

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 1

320--333

EN

The paper presents the results of Gas Metal Arc Welding (GMAW) hardfacing testing performed on three grades of hot working tool steels, namely: 55NiCrMoV7, X37CrMoV5-1 and modified X38CrMoV5-3 grade. Metallographic investigations, mainly microstructural ones, were carried out and hardness profiles were analyzed. The chemical composition was investigated in each individual layer of the hardfaced deposits and the substrate material, in order to obtain a profile representation. The obtained results of profilometric evaluation of the chemical composition showed clear differences in the content of basic and alloying elements in the subsequent weld layers. The diversity of the chemical composition of the substrate material caused that the uniform chemical composition for all tested materials was achieved only in the third, upper weld layer. Despite the variable content of alloying elements and carbon, as well as slight differences in microstructure occurring for individual weld layers, a substantially stable and high hardness was maintained over the entire cross-section of the obtained hardfaced coatings. In the area of the heat-affected zone (HAZ), a decrease in hardness was observed, which is associated with the decomposition of the high-temperature tempered martensite and the spheroidization of the microstructure.

3

Tribology Characteristics of Heatproof Alloys at a Dynamic Pin Ladening in the Variable Temperature Field

Bembenek Michał, Tsyganov Volodymyr, Sakhniuk Nataliia, Lazarieva Olha, Machnik Ryszard, Ropyak Liubomyr

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 5

140--152

EN

An analysis of the operating conditions of gas turbine engines, their components, and the destruction causes was carried out. The designer problems of tribo-joints operating under difficult conditions of force and temperature loads are singled out. The study aimed at obtaining the comparable quantitative dependences of blade material wear, taking into account the role of both cyclical changes in the temperature of the gas flow under the conditions close to real ones, and their frictional characteristics. Deformable heat-resistant nickel alloys and foundry heat-resistant nickel alloys from which T-shaped samples were made, were chosen for the research. The tests were carried out on the developed gas dynamic stand, which simulates the working conditions of the bandage joints of the bladed turbomachines of gas turbine installations. The intensity of wear was determined as the ratio of the worn material volume to the number of load cycles under different temperature conditions. The wear resistance of three-way connections operating under the conditions of non-stationary thermal loads and fluctuations in the contact was considered. It was shown that thermal cycling leads to a decrease in the wear resistance of heat-resistant nickel alloys by 2–3 times and depends on the average temperature of the cycle. It was found that resistance to the wear, and also the character of change of coefficient of friction is mainly determined by the terms of education and destruction of the protective superficial layer. Basic factors managing tribology processes in the zone of contact were determined.

4

Hardfacing of mild steel with wear-resistant Ni-based powders containing WC particles using PPTAW technology

Appiah Augustine, Bialas Oktawian, Jędrzejczyk Marcelina, Ciemała Natalia, Wantuch Łucja, Żuk Marcin, Czupryński Artur, Adamiak Marcin

Welding Technology Review

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2022

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R. 94

3--18

EN

This study explores the use of powder plasma transferred arc welding (PPTAW) as a surface layers deposition technology to form hardfaced coatings to improve upon the wear resistance of mild steel. Hardfaced layers/coatings were prepared using the PPTAW process with two different wear-resistant powders: PG 6503 (NiSiB+60% WC) and PE 8214 (NiCrSiB+45% WC). By varying the PPTAW process parameters of plasma gas flow rate (PGFR) and plasma arc current, hardfaced layers were prepared. Microscopic examinations were carried out to investigate the microstructure and surface characteristics of the prepared hardfaced layers. Penetration tests were performed to ascertain the number and depth of crack sites in the prepared samples by visual inspection. The hardness of the hardfaced layers were determined: hardfacings prepared with PG 6503 had hardness of 46.3 - 48.3 HRC, those prepared with PE 8214 had hardness of 52.7 - 58.3 HRC. The microhardness of the matrix material was in the range of 573.3 - 893.0 HV, and the carbides had microhardness in the range of 2128.7 - 2436.3 HV. Abrasive wear resistance tests were carried out on each prepared sample to determine their relative abrasive wear resistance relative to the reference material, abrasion resistant heat-treated steel, Hardox 400, having a nominal hardness of approximately 400 HV. Findings from the research showed that the wear resistance of the mild steel was improved after deposition of hardfaced layers; the hardness and wear resistance were increased upon addition of Cr as an alloying element; increasing the PGFR increased the hardness and wear resistance of the hardfacings, as well as increase in the number of cracks; increasing the PTA current resulted in hardfacings with less cracks, but relatively lowered the wear resistance. The wear mechanisms were discussed.

5

Increasing the wear resistance of mining machines equipment tools by FCAW with Fe-Mo-Mn-B-C hardfacing alloys

Prysyazhnyuk Pavlo, Krauze Krzysztof, Romanyshyn Liubomyr, Mosora Yurii

Mining Machines

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2022

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vol. 40, iss. 2

64--70

EN

In this study hardfacing by flux-cored arc welding with Fe-Mo-Mn-B-C-based alloy as an alternative technique for improving wear resistance of mining machines conical picks was investigated. The microstructure of hardfaced layer consists of the uniformly distributed faceted grains of binary (Fe,Mn)Mo2B2 boride phase with average size of 25 μm and austenite-based eutectic. The hardness measured by microindentation and microscratching techniques across the interfaces between deposited layer and base steel was within 2.2 – 18 GPa. No welding defects such as cracks, pores or non-metal inclusions in the hardfaced layer and heat affected zones were detected. Comparative studies of the developed hardfacing alloy with commercially available Capilla HR MAG hardfacing and heat treated 35HGS steel were carried out using testing machine developed at the department of machinery engineering and transport of AGH university of science and technology for semi-industrial wear tests of mining machines conical picks. Wear measurement results show that using hardfacing with proposed alloy of Fe-Mo-Mn-B-C system leads to decreasing of impact-abrasion wear rate in approximately 3 times than that for tested commercial materials. This allows to recommend hardfacing by FCAW with proposed material in form of flux-cored wire for conical picks insert holders’ surfaces during mining of hard rocks.

6

Quantitative assessment of the influence of plasma hardfacing parameters on the metallurgical melting of an austentic steel coating with a substrate material made of C45 steel

Bazychowska Sylwia, Starosta Robert, Dudzik Krzysztof

Journal of KONBiN

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2022

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Vol. 52, iss. 3

27--51

EN

In this paper, based on a quantitative analysis of the parameters of plasma hardfacing of C45 steel with CastoMag 45554S wire, an optimisation of the hardfacing process parameters has been carried out. Experimental researches were carried out on the basis of an orthogonal plan, and the optimum hardfacing parameters, e.g.: intensity, voltage, wire feeding speed, were determined by the multiple regression method and the Taguchi method. It was found that the main current of the plasma arc had the greatest influence on the value of the fusion index. The highest S/N value was obtained for the following parameters: I = 120 A, U = 31 V, vn = 0.75 m/min, vd = 3.9 m/min, z = 12 mm.

PL

W oparciu o ilościową analizę parametrów napawania plazmowego stali C45 drutem CastoMag 45554S dokonano optymalizacji parametrów procesu napawania. Badania realizowano na podstawie planu ortogonalnego, a optymalne parametry napawania np.: natężenie, napięcie, prędkość podawania drutu zostały wyznaczone metodą regresji wielokrotnej oraz metodą Taguchi. Ustalono, że największy wpływ na wartość współczynnika wtopienia ma natężenie prądu głównego łuku plazmowego. Największą wartość współczynnika S/N uzyskano przy parametrach: I = 120 A, U = 31 V, vn = 0,75 m/min, vd = 3,9 m/min, z = 12 mm.

7

Investigating the Possibility of Regenearation by Hardfacing for Forging Tools Based on Analysis of Tool Working Conditions and Wear Evaluationy

Widomski Paweł, Kaszuba Marcin, Krawczyk Jakub, Nowak Bartłomiej, Lange Artur, Sokołowski Paweł, Gronostajski Zbigniew

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 4

1395--1410

EN

Tests were performed on example tools applied in hot die forging processes. After withdrawal from service due to excessive wear, these tools can be regenerated for re-use through machining and hardfacing. First, analysis of worn tools was carried out for the purpose of identifying tool working conditions and wear mechanisms occurring in the surface layer of tools during forging. Testing of worn tools included observations under a microscope, surface scanning and microhardness measurement in the surface layer. The results indicate very diverse work conditions, which suggest the application of different materials and hardfacing tool regeneration technology in individual die forging processes.

8

Using FCAW with Electrodes Based on Fe-Ti-Mo-B-C System for Increasing of Durability of Junk Removal Tools

Ivanov Olexandr, Prysyazhnyuk Pavlo, Romanyshyn Liubomyr, Romanyshyn Taras, Mosora Yurii

Multidisciplinary Aspects of Production Engineering

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2021

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Vol. 4, Iss. 1

132--141

EN

In this work were analyzed factors and working conditions that leads to the wearing of junk mills tools that are a part of junk removal equipment used in drilling and workover of borehole. Such equipment is a part of oil and gas industry and work under condition of intense abrasive wearing with increased pressures and cyclic loads. Was established that traditional hardfacing materials based on the Fe-Cr-C system are not effective for improvement of abrasion resistance of elements of such equipment due to their low crack resistance and low hardness of chromium carbides. The aim of this work was to increase a durability of that equipment by using of flux cored electrodes with reaction components of pure metal powders, which leads to forming the fine-grained structure with increased hardness. Powders of Ti, Mo, B4C and their combinations were used. Structures of the hardfacing coatings were investigated by method of metallography, scanning electron microscopy (SEM). Abrasion wear tests were held under condition of fixed and non-fixed abrasion. Using of pure metal powders led to formation of a fine-grained structure with grains of Mo2FeB2 that forms around TiC, which work as modifier. It was investigated that the researched material based on Fe-Ti-Mo-C-B system that was used for increasing the wear resistance of junk mills led to increasing of the TBO period in 1.5-1.6 times comparing with serial hardfacing materials based on tungsten.

9

The Analysis of Filler Material Effect on Properties of Excavator Crawler Track Shoe after Welding Regeneration

Gucwa M., Winczek J., Wieczorek P., Mičian M., Koňár R.

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 1

31--36

EN

The application of hardfacing is one of the ways to restore the functional properties of worn elements. The possibility of using filler materials rich in chrome allows for better wear resistance than base materials used so far. The paper presents the results of research on the use of 3 different grades of covered electrodes for the regeneration of worn track staves. The content of the carbon in the covered electrodes was from 0,5% to 7% and the chromium from 5% to 33%. The microscopic and hardness tests revealed large differences in the structure and properties of the welds. The differences in the hardness of the welds between the materials used were up to 150 HV units. The difference in wear resistance, in the ASTM G65 test, between the best and worst materials was almost 12 times big.

10

Arc welding renovation of permanent steel molds

Šutka Jozef, Koňar R., Moravec J., Petričko L.

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 2

35--40

EN

The paper deals with the possibility of the renovation of permanent steel molds for casting using electric arc welding technology. When casting liquid metal into permanent steel molds, there is chemical-thermo-mechanical wear of the surface of the mold cavity and the inlet system, which causes a deterioration of the surface quality and dimensional accuracy of the casting. For this reason, it is necessary to renovate the steel mold after a certain casting interval - mold life. In this case, the technology of manual electric arc welding with a coated electrode was used for the renovation. The welding renovation aims to increase the service life of the mold using carbide hardfacing welds, which after welding achieve high mechanical properties of the renovated mold parts. Two types of hardfacing coated electrodes were used for welding, namely the OK Weartrode 55HD electrode and the OK Weartrode 50T electrode. Macroscopic analysis, tribological tests as well as the measurement of the hardness of the welded layers were performed to evaluate the quality and the friction coefficients of the additional materials used. The properties of hardfacing welds were compared with the properties of the basic material of the high-alloy steel mold. The main advantage is in addition to increasing the durability and longevity of the mold, also reducing the cost of mold renovation compared to other renovation technologies.

11

Factors Influencing Cavitation Erosion of NiCrSiB Hardfacings Deposited by Oxy-Acetylene Powder Welding on Grey Cast Iron

Szala Mirosław, Walczak Mariusz, Hejwowski Tadeusz

Advances in Science and Technology. Research Journal

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2021

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Vol. 15, no 4

376--386

EN

The work presents the results of a study on cavitation erosion (CE) resistance of two NiCrSiB self-fluxing powders deposited by oxy-acetylene powder welding on cast iron substrate grade EN-GJL-200. The mean hardness of deposits A-NiCrSiB, C-NiCrSiB is equal to 908 HV, 399 HV and exceeds those of EN-GJL-200 and X5CrNi18-10 reference specimens 197 HV and 209 HV, respectively. To study CE, the vibratory apparatus has been used and tests were conducted according to the ASTM G32 standard. Cavitation eroded surfaces were examined using a profilometer, optical and scanning electron microscopy. The research indicated that the CE resistance, expressed by the cumulative mass loss decreased in the following order C-NiCrSiB > A-NiCrSiB > X5CrNi18-10 > EN-GJL-200. Therefore, hardfacings were characterised by lower cumulative mass loss, in turn, higher CE resistance than the reference sample and therefore they may be applied as layers to increase resistance to cavitation of cast iron machine components. Results indicate that in the case of multiphase materials, hardness cannot be the main indicator for CE damage prediction while it strongly depends on the initial material microstructure. To qualitatively estimate the cavitation erosion damage (CEd) of NiCrSiB self-fluxing alloys at a specific test time, the following factors should be considered: material microstructure, physical and mechanical properties as well as surface morphology and material loss both estimated at specific exposure time. A general formula for the CEd prediction of NiCrSiB deposits was proposed.

12

The use of a measuring arm with a laser scanner for analysis and support of regenerative surfacing processes of forging dies

Kaszuba Marcin D., Widomski Paweł, Kiełczawa Tomasz, Gronostajski Zbigniew

Welding Technology Review

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2020

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R. 92, nr 3

23--32

EN

The article presents the results of research conducted in order to develop the technology of regenerative surfacing of forging dies. The selected example shows how the use of a measuring arm with a laser scanner can be used to support the regeneration process. The tests were conducted in industrial conditions of a forging die. The analysis of the regeneration process was carried out at each of 4 stages: after wear in the forging process, after initial machining, after regenerative surfacing and after final machining. It has been shown that scanning can be used to develop programs for mechanical pre-treatment, to measure the volume of padding welds, to determine the amount of finishing allowance, to verify the effectiveness of the surfacing process and to control the quality of the die before the forging process. The obtained results confirmed the effectiveness of the regeneration carried out. In terms of performance, it has been shown that too much padding weld's material is a machining allowance. For this reason, the treatment is time and energy consuming and about 68% of the padding weld's material is waste or chips. The analysis showed the possibility of saving up to 45% of the weld metal material by using reasonable allowances of smaller thickness. These results indicate the need to modify the regeneration technology and the legitimacy of using robotic surfacing, which can provide greater precision and repeatability in the laying of padding weld’s beads. The next stage of research will be robotization of the analyzed forging die regeneration process using WAAM technology.

PL

Artykuł prezentuje efekty badań prowadzonych w celu rozwoju technologii napawania regeneracyjnego matryc kuźniczych. Na wybranym przykładzie pokazano w jaki sposób zastosowanie ramienia pomiarowego ze skanerem laserowym może służyć do wspomagania procesu regeneracji. Badania prowadzono w przemysłowych warunkach kuźni matrycowej. Analizę procesu regeneracji prowadzono na każdym z 4 etapów: po zużyciu w procesie kucia, po wstępnej obróbce mechanicznej, po napawaniu regeneracyjnym oraz po wykańczającej obróbce mechanicznej. Wykazano, że skanowanie może być wykorzystywane do opracowania programów wstępnej obróbki mechanicznej, do pomiaru objętości napoin, do określenia wielkości naddatku na obróbkę wykańczającą oraz do weryfikacji skuteczności procesu napawania i kontroli jakości matrycy przed procesem kucia. Uzyskane wyniki potwierdziły skuteczność przeprowadzonej regeneracji. W aspekcie wydajności wykazano, że zbyt wiele materiału napoiny stanowi naddatek pod obróbkę mechaniczną. Z tego powodu obróbka jest czaso- i energochłonna a ok. 68% materiału napoiny stanowi odpad czyli wióry. Przeprowadzona analiza wykazała możliwość zaoszczędzenia do 45% materiału stopiwa przy zastosowaniu rozsądnych naddatków o mniejszej grubości. Wyniki te wskazują na konieczność modyfikacji technologii regeneracji oraz zasadność stosowania napawania zrobotyzowanego, które może zapewnić większą precyzję i powtarzalność przy układaniu ściegów napoiny. Kolejnym etapem badań będzie robotyzacja analizowanego procesu regeneracji matrycy kuźniczej przy wykorzystaniu technologii WAAM.

13

The effect of the preheating on to properties of the wear resistant welds

Gucwa Marek, Winczek Jerzy, Mičian Miloš

Welding Technology Review

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2020

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R. 92, nr 2

7--14

EN

Wear resistant welds are used in many industries when it is necessary to protect machine components and structures against wear caused by operating conditions. Often the main parameter determining the usefulness of these welds is high hardness reaching about 60 HRC. In many cases, after the surfacing process, a mesh of cracks is formed in the surface layer, which can affect the durability of the hard-wearing layers used. The paper presents the analysis of the influence of preheating up to 400 °C on the properties of welds and its effect on the number of cracks in the surface layer. The use of preheating allowed to reduce the number of cracks in the padding weld to 1. The optimum heating temperature was 200 °C, for which the number of cracks have been reduced and the lowest wear was recorded.

PL

Napoiny trudnościeralne są wykorzystywane w wielu gałęziach przemysłu, gdy zachodzi konieczność ochrony elementów maszyn i konstrukcji przed zużyciem wywołanym warunkami eksploatacji. Często głównym parametrem określającym przydatność tych napoin jest wysoka twardość sięgająca ok. 60 HRC. W wielu przypadkach po procesie napawania powstaje w warstwie wierzchniej siatka pęknięć, która może wpływać na trwałość stosowanych warstw trudnościeralnych. W pracy przedstawiono analizę wpływu podgrzewania wstępnego do 400 °C na właściwości napoin oraz jego wpływu na ilość pęknięć w warstwie wierzchniej. Zastosowanie podgrzewania wstępnego pozwoliło zredukować ilość pęknięć w napoinie do 1. Optymalną temperaturą podgrzewania było 200 °C, dla której zanotowano zmniejszenie ilości pęknięć oraz najmniejsze zużycie.

14

Structural investigation of the Plasma Transferred Arc hardfaced glass mold after operation

Skowrońska Beata, Sokołowski Wojciech, Rostamian Reyhaneh

Welding Technology Review

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2020

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R. 92, nr 3

55--65

EN

The paper presents the results of research aimed at detecting the causes of premature wear of molds for glass shaping, manifesting the formation of pits in the Plasma Transferred Arc pad-welds in which the working surface of the mold was shaped. The weld microstructure was tested, the chemical composition was determined in the pad-weld’s cross-section, linear and surface chemical distributions were made in the pad-weld’s cross-section, the surface morphology in damaged areas, and the chemical composition of surface inclusions were examined. The too high temperature of formed glass associated with wettability of the glass of the mold was indicated as the primary cause of premature mold wear.

PL

W artykule przedstawiono wyniki badań ukierunkowanych na wykrycie przyczyn przedwczesnego zużycia form do kształtowania szkła, objawiające się powstawaniem wżerów w napoinie plazmowej, w której ukształtowano powierzchnię roboczą formy. Przeprowadzono badania mikrostruktury napoiny, określono skład chemiczny w przekroju napoiny, wykonano liniowe i powierzchniowe rozkłady pierwiastków chemicznych w przekroju napoiny, zbadano morfologię powierzchni w obszarach uszkodzonych, zbadano skład chemiczny wtrąceń na powierzchni. Jako podstawową przyczynę przedwczesnego zużycia form wskazano zbyt wysoką temperaturę formowanego szkła powiązaną ze zwilżalnością szkłem formy.

15

Wear Resistance Improvement of Equipment for Production of Building Ceramics by Hardfacing with Flux-Coerd Electrodes based on Fe-Ti-B-C System

Prysyazhnyuk Pavlo, Ivanov Oleksandr, Lutsak Dmytro, Lutsak Lyubomyr

Multidisciplinary Aspects of Production Engineering

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2020

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Vol. 3, Iss. 1

263--273

EN

In this work were analyzed factors that leads to wearing of equipment of production engineering, construction, oil and gas, woodworking, tillage industries. Was established that traditional hardfacing materials based on the Fe-Cr-C system are not effective for improvement of abrasion resistance of elements of equipment for production of ceramic building materials due to working conditions. The aim of this work was to increase a durability of that equipment by using of flux cored electrodes with reaction components that provide “in-situ” synthesis, which leads to fine-grained structure of refractory borides and carbides and their solid solutions with increased hardness. Powders of Ti, Mo, B4C and their combinations were used. Structure of the hardfacing coatings were investigated by method of metallography, scanning electron microscopy (SEM). Using of pure metal powders led to forming a fine-grained structure with refractory borides and carbides and their solid solutions. It was investigated that the offered material based on Fe-Ti-Mo-C-B system used for increasing the wear resistance of extruder-screw for production of ceramic building material can increase the TBO period in 2.2-2.4 times in comparison with serial hardfacing materials based on Fe-Cr-C system.

16

Thermodynamic approach to the development and selection of hardfacing materials in energy industry

Shihab Thaer, Prysyazhnyuk Pavlo, Semyanyk Iryna, Anrusyshyn Roman, Ivanov Olexandr, Troshchuk Lyubomyr

Management Systems in Production Engineering

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2020

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nr 2 (28)

84--89

EN

The overall study objection is selection and optimization all available thermodynamic data required for using calculation of phase diagram (CALPHAD) technique within the Fe-C-Cr-Mn-Si-Ti system. Such data collected in the thermodynamic database can be used for predicting the phase constitution states of a given composition for Fe-based hardfacing materials, which often use in energy industry in order to increase the abrasion and impact wear resistance of equipment parts. In order to compare theroretical calculation results with experimental data, four different types of hardfacing were deposited using flux-cored arc welding. Microstructure and chemical composition of deposited layers was investigated using optical and scanning electron microscopy together with energy dispersive X-ray spectroscopy. Comparison of experimental and computed results shows that they are in good agreement in meaning of presence of all-important phase equilibrium regions. The developed database can be used for rational selection of hardfacing materials for energy industry equipment and reasonable choice of new alloying systems.

17

Hardfacing of metal-cutting tools by arc welding in vacuum

Ferdinandov N. V., Gospodinov D. D.

Journal of Achievements in Materials and Manufacturing Engineering

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2020

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Vol. 99, nr 2

49--56

EN

Purpose: To present a technology for hardfacing of metal-cutting tools by arc welding in vacuum. Design/methodology/approach: The experiments were carried out using an installation for arc welding in vacuum. Objects of research were metal cutting tools (lathe knives), made of high-speed steel HS6-5-2 on a base metal of structural steel C45. The structure, hardness and wear resistance after hardfacing and after a triple tempering at 560°C have been determined. The heat resistance of the obtained instruments has been examined. Findings: The microstructural analysis showed that the structure of the built-up layer consisted of martensite, retained austenite and carbides. This was confirmed by the values of measured hardness after welding which were about 63-64 HRC. The triple tempering led to an increase in hardness by 3-4 HRC. It was found that the built-up layers (cutting edges of tools) retain their hardness (HRC=63-65) up to a temperature of 615-620°C, which shows that the heat resistance of the build-up layers was similar to that of the hardened and tempered tools of the same steel. The built-up work-pieces (excluding heat treated) and the reference knife showed the same cutting qualities at cutting speeds in the range of 55 to 120 m/min. It has been found that triple tempering after hardfacing led to increased wear resistance and consequently the durability of the tool also increased due to the higher hardness. Practical implications: The practical application is related to the production of metalcutting tools. Originality/value: The proposed technological method allows to produce defects free built-up layers. The cutting properties of the built-up in vacuum layers are comparable to or better than those of new tools made of steel HS 6-5-2.

18

Hardfacing of copper

Babinets Anatoliy A., Ryabtsev Igor A., Ryabtsev Igor I., Turyk Eugeniusz, Perepletchikov Evgeniy F., Lentyugov Ivan P.

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2020

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Vol. 64, No. 6

7--17

EN

The article discusses the primary issues of the hardfacing of copper elements exposed to intense abrasive wear, gas-abrasive wear at high temperature and in contact with liquid metal. In addition, the article presents test results concerning the surfacing of copper grade M1 performed using a self-shielded fluxcored wire providing weld deposit Fe14 and plasma powder surfacing performed using powder providing weld deposit Ni3 ((in accordance with EN 14700).

PL

Omówiono zasadnicze problemy napawania utwardzającego części miedzianych eksploatowanych w warunkach intensywnego zużycia ściernego i gazowo-ściernego w wysokiej temperaturze oraz w kontakcie z ciekłym metalem. Przedstawiono wyniki badań dotyczących napawania miedzi M1 samoosłonowym drutem proszkowym zapewniającym stopiwo typu Fe14 oraz napawania metodą plazmowo-proszkową z użyciem proszku zapewniającego stopiwo Ni3 wg normy EN 14700.

19

Properties of new-generation hybrid layers combining hardfacing and nitriding dedicated to improvement in forging tools’ durability

Kaszuba Marcin, Widomski Paweł, Białucki Piotr, Lange Artur, Boryczko Bożena, Walczak Mariusz

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 3

212--223

EN

This article deals with the subject of layers produced in a hybrid process combining hardfacing and nitriding. These layers are characterized by improved resistance to wear, which arises from the synergy between favorable materials during hardfacing and nitriding treatment. Tests were conducted on hot-work tool steel (H11) samples. Hardfaced layers consisting of three layers were applied to these samples, where layers were made from two materials-Robotool 46 and Hardface VMolc powder wires. Next, samples of both materials were nitrided using ZeroFlow gas nitriding technology, with control of potential aimed at obtaining a diffusion layer without a white zone of nitrides on the surface. The next step was to investigate the properties of hardfaced layers and of layers hardfaced after nitriding treatment. Conducted tests covered observations of the microstructure, microhardness measurements as a function of distance from the surface, measurement of stresses in the surface layer by means of X-ray diffraction, and tribological tests. Obtained test results show that hybrid layers combining hardfacing and nitriding may be suitable for improving the lifetime of tools applied in hot forging processes.

20

The laboratory tests of hybrid layers combining hardfacing and nitriding dedicated to increase the durability of forging tools in hot forging processes

Widomski Paweł, Gronostajski Zbigniew, Kaszuba Marcin, Kowalska Jagoda, Pawełczyk Mariusz

Welding Technology Review

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2019

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R. 91, nr 2

1--6

EN

In response to the growing need to use wear-resistant layers that increase durability of tools in forging processes, hybrid layers have been proposed that combine hardfacing with nitriding treatment. This article presents the results of laboratory tests of surface wear-resistant layers made with a new hybrid technology Gas-Shielded Metal Arc surfacing (hardfacing) with ZeroFlow gas nitriding. Specimens made with hardfacing or nitriding were prepared and examined. Analysis covered the thorough microstructure study, EDX chemical composition analysis and microhardness analysis. In experiment, 3 different types of nitrided layers were proposed for alpha, gamma prim and epsilon nitrides in the surface layer. The results of metallographic research in the surface layer was presented. The analysis of chemical composition in the particular overlay welds was performed to determine the content of alloying elements in the particular overlay welds. The susceptibility to nitriding of used weld materials as well as the ability to form particular types of nitrides on selected welded substrates was also tested.

PL

W odpowiedzi na narastające potrzeby stosowania warstw odpornych na zużycie, zwiększających trwałość narzędzi w procesach kucia, zaproponowano warstwy hybrydowe łączące napawanie z późniejszą obróbką azotowaniem. W tym artykule przedstawiono wyniki badań laboratoryjnych warstw odpornych na zużycie wykonanych w nowej technologii hybrydowej łączącej napawanie łukowe z azotowaniem gazowym metodą ZeroFlow. Referencyjne próbki wykonane w technologii napawania lub azotowania zostały także przygotowane i zbadane. Analiza obejmowała analizę mikrostruktury, analizę składu chemicznego EDX i analizę mikrotwardości. W ramach eksperymentu zaproponowano 3 różne typy warstw azotowanych na strefę azotków alfa, gamma prim i epsilon w warstwie wierzchniej. Zaprezentowano wyniki badań metalograficznych oraz analizy składu chemicznego w przekroju napoiny. Na tej podstawie określono udział pierwiastków stopowych w poszczególnych warstwach napoiny. Badano również podatność na azotowanie stosowanych napoin a także zdolność do tworzenia się poszczególnych rodzajów azotków na wybranych napawanych podłożach.