Wyniki wyszukiwania - BazTech

1

Developing the inoculation procedure for high-quality cast iron with flake graphite, intended for large-size casting (bottom or distance plates and counterweights) – produced in Krakodlew Foundry S.A.

Guzik Edward, Świątkowski Adrian, Szczęsny Andrzej, Kopyciński Dariusz, Mirek Piotr, Piotrowski Krzysztof

Technical Transactions

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2023

|

Vol. 120, iss. 1

art. no. e2023009

EN

This article presents the first part of the research on the production of large-sizecastings, such as bottom plates and counterweights produced in the KrakodlewS.A. foundry. Castings of this type are not complicated in terms of construction butmust meet certain requirements, namely to be able to withstand the effects of hightemperature and associated stresses, or to have specific dimensions and weight inthe case of counterweights. In both cases, the most common method of formingcastings is horizontal moulding. However, this requires a lot of time for machiningthe finished castings. Forming heavy castings in a vertical orientation, although muchmore problematic, can mean that the amount of time required for machining may bereduced. The research presents the effect of overheating temperature on the effectsof inoculation with the Zircinoc inoculant, in which it was shown that increasing thetemperature by fifty degrees increased the amount of eutectic grains by around11–15%.

2

The Effect of Successive Stages of the Melting Process on the Nucleation of Ductile Cast Iron

Kołakowski Jakub, Brzeżański Mateusz, Burdzy Daniel, Sobieraj J., Urbanowicz M., Paruch T., Janerka Krzysztof

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 1

61--67

EN

The article discusses issues related to the melting of grey and ductile cast iron in terms of metallurgical quality. The derivative and thermal analysis (DTA) was used to assess this quality. The article presents the results of research carried out in industrial conditions and analysed by the Itaca system. In the paper, the effect of the furnace type, the charge materials and the inoculation process on the parameters characterising the cast iron being melted was analysed. The most important of these are the minimum eutectic temperature (Temin), the liquidus temperature (Tliquidus) and the nucleation rate. The results of the research and calculations are shown in graphs and as dependencies. Some of DTA results were compared to the microstructure analysis results. The article shows that the derivative and thermal analysis is a very effective tool in the assessment of the metallurgical quality of cast iron. It is a very good addition to chemical analysis. Based on the results of the research, it was concluded that a very high correlation exists between the rate of nucleation (DTA) and the number of graphite nuclei (microstructure analysis). Furthermore, it was also found that an improvement in nucleation could be achieved by ensuring a high value of carbon equivalent (CE) and, above all, by conducting the primary and secondary inoculation processes, respectively.

3

Designing of X46Cr13 Steel Heat Treatment in Condition of Casting Mould

Przyszlak Natalia, Piwowarski Grzegorz

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 2

119--126

EN

The paper presents issues related to the technology of layered castings manufactured in the system: working part made of high-chromium steel X46Cr13 - base part made of gray cast iron with flake graphite, using the mould cavity preparation technology. Considering the high hardenability of the above-mentioned steel grade, the aim of the research was to optimize the casting parameters of gray cast iron in such a way that it would be possible to perform heat treatment of X46Cr13 steel directly in the casting mould. As part of the research, the geometry of the working and base parts of layered castings was selected, and guidelines for mould technology from the point of view of the moulding sand were developed. In order to control the cooling rate, three matrix of the moulding sand were used - quartz sand, chromite sand and silicon carbide, with the same granularity. The thermal conductivity coefficient of sands made on selected matrix, bound with synthetic resin in the ratio of 30:1, was experimentally determined. Then, the bimetal casting process in a given mass was simulated in the MagmaSoft® (ver. 5.4.1). The purpose of the simulation was to determine the maximum virtual temperature Tm in the thermal center of the outer surface of the X46Cr13 steel insert. From the point of view of the research purpose, the insert was expected to heat up to the austenitization temperature, i.e. at least 950°C.

4

Characterization of deposit layers formed on grey cast iron

Gwoździk Monika

Technical Sciences / University of Warmia and Mazury in Olsztyn

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2022

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nr 25(1)

107--115

EN

This paper presents the results of diagnostic examinations conducted on the water pipe made of grey cast iron that were operated in conditions for 260 thousand hours. The tube was exposed in a soil. The phase composition of the deposit layers formed on both sides of the tube walls (outside and inside) was examined using optical and confocal microscopy and X-ray diffraction. The obtained XRD test results showed that mainly -FeOOH) and γ-FeOOH is formed on the inside of the pipe wall. In turn, on the outside, in addition to the above-mentioned compounds, also SiO2 is formed. The results of these examinations have shown a higher degradation of pipe on the outer side. The arithmetic mean deviation of the profile from the mean line was 6.23 µm and 8.07 µm for the inner and outer side of the pipe wall, respectively. The work demonstrates the usefulness of material science, especially X-ray structure, topography and surface studies, in characterizing the degradation processes of layers formed on gray cast iron exploited in the water supply industry.

5

Analysis of the selected machining factors influence on the milling process of grey cast iron

Ziarkowski Piotr, Klamczyński Kamil, Sójka Radosław, Kowalska Natalia, Błasiak Sławomir, Nowakowski Łukasz, Skrzyniarz Michał

Mechanik

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2022

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R. 95, nr 11

22--29

EN

The quality of the geometric structure of a surface is influenced by factors such as the geometry of the cutting tool, the cutting conditions and the displacements in the tool-workpiece system. This paper describes the results of a study to analyse the influence of selected machining factors accompanying the face milling process on the geometric structure of the surface. During the machining tests, relative displacements in the T-W system were recorded, as well as the components of forces and moments of the face milling process for specimens made of grey cast iron. The tests were carried out on an AVIA VMC 800 milling centre, and the accuracy of the machined surface was checked. A Talysurf CCI - Lite Non-contact 3D Profiler, which was equipped with TalyMap Platinum software, was used to measure the geometric structure of the surface.

PL

Na jakość struktury geometrycznej powierzchni wpływają takie czynniki, jak: geometria narzędzia skrawającego, warunki skrawania oraz przemieszczenia w układzie narzędzie-przedmiot obrabiany. W artykule opisano wyniki badań, których celem była analiza wpływu wybranych czynników obróbki towarzyszących procesowi frezowania czołowego na strukturę geometryczną powierzchni. W trakcie prób skrawania rejestrowano przemieszczenia względne w układzie N-P oraz składowe sił i momentów procesu frezowania walcowo-czołowego próbek wykonanych z żeliwa szarego. Próby przeprowadzono na centrum frezarskim AVIA VMC 800. Sprawdzono dokładność wykonania powierzchni poddanej obróbce frezarskiej. Strukturę geometryczną powierzchni zmierzono profilometrem Talysurf CCI - Lite Non-contact 3D Profiler, wyposażonym w oprogramowanie TalyMap Platinum.

6

Inoculation of Gray Cast Iron Intended for Large Scale and Heavy Weight Castings of Bottom Plates and Counterweights Manufactured in the KrakOdlew S.A.

Szczęsny Andrzej, Kopyciński Dariusz, Guzik Edward

Archives of Foundry Engineering

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2022

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Vol. 22, iss. 3

19--24

EN

The paper presents research carried out during the development of new technology for the production of heavy-weight castings of counterweights. The research concerns the procedure of inoculation gray cast iron with flake graphite and indicates guidelines for the development of new technology for obtaining inoculated cast iron for industrial conditions. The research was conducted in order to verify the possibility of producing large size or heavy-weight castings of plates in a vertical arrangement. The aim is to evenly distribute graphite in the structure of cast iron and thus reduce the volumetric fraction of type D graphite. The tests were carried out using the ProCast program, which was used to determine the reference chemical composition, and the inoculation procedure was carried out with the use of three different inoculants. The work was carried out in project no. RPMP.01.02.01-12-0055 / 18 under the Regional Operational Program of the Lesser Poland Voivodeship in Krakow (Poland).

7

The Importance of TDA Thermal Analysis in an Automated Metallurgical Process

Petrus Łukasz, Bulanowski Andrzej, Kołakowski Jakub, Sobieraj Jakub, Paruch Tomasz, Urbanowicz Mariusz, Brzeżański Mateusz, Burdzy Daniel, Zych Jerzy, Janerka Krzysztof

Journal of Casting & Materials Engineering

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2021

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Vol. 5, no. 4

89--93

EN

The article presents the results of research and work related to the implementation of the research and development project POIR.01.01.01-00-0120/17 co-financed by the EU, through the NCBR, entitled: Innovative technology using thermal analysis, TDA, of self-feeding manufacturing of high-quality cast iron to produce new generation, enhanced performance casts. In many foundries, thermal derivative analysis (TDA) is used in addition to chemical analysis to evaluate the physical and chemical properties of an alloy while it is still in the melting furnace or ladle and before it is poured into the mold. This fact makes it possible to improve the metallurgical quality of the alloy by introducing alloying additives, carburizers or modifiers into the furnace as part of the pre-modification or primary or secondary modification in the ladle or when pouring into molds. Foundry machinery (modifier dosing systems and spheroidizing station) is very important in these operations. Only the full synergy of modern equipment with modern technology ensures high quality and repeatability of the casting process. The article mainly discusses the obtained parameters of TDA analysis (with the use of the ITACA system) at different stages of melting and how to improve them by using modern and fully automated dosing systems (Itaca OptiDose, ItacaWire and ItacaStream). Special attention was paid to the minimum temperature of the eutectoid. The change of its value after the modification process, its influence on the quality of the melted metal, a very strong correlation with the number of nuclei and the number of graphite precipitations in the casts were shown.

8

Influence of Molding Materials on the Self-Hardening of X46Cr13 Steel / Grey Cast Iron Bimetallic Castings

Przyszlak N., Wróbel T., Dulska A.

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 1

43--50

EN

The paper presents the problem which concerning the technology of bimetallic castings in materials configuration: high-chromium steel as the working layer and grey cast iron as the base part. The aim of the studies was integrate the process of manufacturing of bimetallic casting with the heat treatment of hardening type of X46Cr13 steel insert by applying the mould with sandmix on a matrix of chromite sand. Range of studies included the chemical composition analysis, non-destructive ultrasonic tests to examine the quality of the permanent bond between the working layer (steel insert) and the base part (grey cast iron) of the bimetallic castings, hardness measurements as well as metallographic examinations performed on the optical and scanning electron microscopes. On the basis of obtained results was concluded that the self-hardening process occurred in the X46Cr13 steel working layer and in result of this the hardness on its surface equalled approx. 45HRC in case of the bimetallic castings with full permanent bond between both parts.

9

Comparison of tribological properties and structure of coatings produced in powder flame spraying process on grey cast iron

Czupryński Artur, Adamiak Marcin, Bayraktar Emin, Wyględacz Bernard

Welding Technology Review

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2020

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R. 92, nr 3

7--21

EN

In this article results of tribological and structural properties comparison of flame sprayed, by SupJet-S-Eutalloy® multipurpose system, two self-fluxing alloys of Ni-B-Si type in the form of powder for spraying with remelting are presented. Layers were produced on EN-GJL-250 grade grey cast iron with flake graphite in an austenitic matrix. Abrasive wear resistance examination acc. to ASTM G65-00 and erosive wear resistance examination acc. to ASTM G76-2 were performed. Obtained results were compared with abrasion-resistant steel Hardox® 400. Macro- and microscopic examination were carried enabling layer quality evaluation and structure of examined layer and base material determination. X-ray microanalysis was performed to obtain qualitative and quantitative data about microareas chemical composition. The Eutalloy® BronzoChrom 10185 powder flame sprayed layer with higher Boron and Silicon content was characterized by 13% lower wear intensity under mineral abrasive conditions and about 30% higher erosion wear resistance than Eutalloy® NiTec 10224 powder flame sprayed layer.

PL

W artykule przedstawiono wyniki badań dotyczące porównania właściwości tribologicznych i strukturalnych powłok, natryskiwanych płomieniowo za pomocą wielofunkcyjnego systemu SupJet-S-Eutalloy® dwoma różniącymi się składem chemicznym samotopnikującymi stopami typu Ni-B-Si w postaci proszku metalicznego przeznaczonego do natrysku z jednoczesnym przetopieniem. Powłoki wykonano na podłożu z żeliwa szarego gatunku EN-GJL-250 z grafitem płatkowym w osnowie austenitycznej. Przeprowadzono badania odporności na zużycie ścierne wg normy ASTM G65-00 oraz odporności na zużycie erozyjne zgodnie z normą ASTM G 76-2. Uzyskane wyniki porównano z parametrami zużycia abrazyjnego stali trudnościeralnej Hardox® 400. Wykonano obserwacje metalograficzne makro i mikroskopowe pozwalające na określenie jakości powłok oraz struktur badanych warstw i materiału podłoża. W celu określenia jakościowego i ilościowego składu chemicznego mikroobszarów powłok przeprowadzono badania metodą mikroanalizy rentgenowskiej. Stwierdzono, że powłoka natryskiwana płomieniowo proszkiem Eutalloy® BronzoChrom 10185 zawierającym większe stężenie boru i krzemu wykazywała o ok. 13% mniejszą intensywność zużycia pod wpływem oddziaływania ścierniwa mineralnego oraz o ok. 30% większą odporność na zużycie erozyjne niż powłoka natryskiwana płomieniowo proszkiem Eutalloy® NiTec 10224.

10

Prediction of Microstructure of Grey Cast Irons by Electrical Resistivity Measurements

Petrič M., Mrvar P., Kastelic S.

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 1

365--369

EN

The paper describes the influence of graphite shape, size and amount to electrical properties of different cast irons. Experiments of electrical resistivity measurements were conducted during solidification of four different melts in different time intervals from melt treatment by inoculation and nodularization. Metallographic analyses were made in order to determine the shape, size, distribution and amount of graphite and correlate results with electrical resistivity measurements. It was found out that nodular graphite is giving the lowest electrical resistivity and is decreased during solidification. Electrical resistivity of lamellar cast iron is increased during solidification since lamellas interrupt metal matrix severely. There is no significant difference in resistivity of vermicular cast iron from nodular cast iron. Smaller size of graphite and lower amount of graphite and higher amount of metal matrix also decrease resistivity.

11

The Influence of the Shape of Graphite Precipitates on the Cast Iron Abrasion Resistance

Jakubus A., Soiński M. S.

Archives of Foundry Engineering

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2019

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iss. 4

87--90

EN

The paper presents the initial results of investigation concerning the abrasion resistance of cast iron with nodular, vermicular, or flake graphite. The nodular and vermicular cast iron specimens were cut out of test coupons of the IIb type with the wall thickness equal to 25 mm, while the specimens made of grey cast iron containing flake graphite were cut out either of special casts with 20 mm thick walls or of the original brake disk. The abrasion tests were carried out by means of the T-01M tribological unit working in the pin-on-disk configuration. The counterface specimens (i.e. the disks) were made of the JT6500 brand name friction material. Each specimen was abraded over a distance of 4000 m. The mass losses, both of the specimens and of the counterface disks, were determined by weighting. It was found that the least wear among the examined materials was exhibited by the nodular cast iron. In turn, the smallest abrasion resistance was found in vermicular cast iron and in cast iron containing flake graphite coming from the brake disk. However, while the three types of specimens (those taken from the nodular cast iron and from grey cast iron coming either from the special casts or from the brake disk) have almost purely pearlitic matrix (P95/Fe05), the vermicular cast iron matrix was composed of pearlite and ferrite occurring in the amounts of about 50% each (P50/Fe50). Additionally, it was found that the highest temperature at the cast iron/counterface disk contact point was reached during the tests held for the nodular cast iron, while the lowest one occurred for the case of specially cast grey iron.

12

The Impact of Selected Geometry Parameter of Titanium Spatial Insert on the Surface Layer Formation on Grey Cast Iron

Dziwoki G., Dulska A., Szajnar J., Król M.

Archives of Foundry Engineering

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2019

|

iss. 1

58--62

EN

The paper presents a method of producing a grey cast iron casting locally reinforced with a titanium insert printed using SLM method (Selective Laser Melting). This article attempts to examine the impact of the selected geometry of titanium spatial insert on the surface layer formation on grey cast iron. The scope of the research focuses on metallographic examination - observation and analysis of the structure of the reinforced surface layer on a light and scanning microscope and a hardness measurement of the titanium layer area. Based on the obtained results, it was concluded that the reaction between titanium insert and metal (grey cast iron) locally develops numerous carbides precipitation (mainly TiC particles), which increases the hardness of the reinforced surface layer and local strengthening of the material. The ratio between the thickness of the support part (grey cast iron) and the working part (titanium insert) affects the resulting layers connection structure. The properties of the obtained reinforced surface layer depend mainly on the geometry of the insert (primarily on the internal dimensions of the connector) and the volume of the casting affecting the re-melting of the insert. A more concentrated structure of carbides precipitation occurs in castings with a full connector insert.

13

Self-hardening of X46Cr13 Steel Integrated with Base from Grey Cast Iron in Bimetallic System

Przyszlak N., Wróbel T.

Archives of Foundry Engineering

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2019

|

iss. 2

29--34

EN

The paper presents the technology of manufacturing layered castings, consisting of grey cast iron (base part) and high-chromium stainless steel (working part/layer). The aim of researches was an attempt of integration of heat treatment of steel X46Cr13 grade with founding of grey cast iron in bimetallic system and determination of the influence of cooling rate of bimetallic system in classical sand mould with bentonite on microstructure and hardness of the working layer. The castings were manufactured using mould cavity preparation method, where steel plate was poured by grey cast iron using different pouring temperature and thickness of base part. Then, the quality of joint between cast iron and steel plate was estimated by using ultrasonic non-destructive testing. The efficiency of heat treatment process was analysed by measurement of hardness and in metallographic examination. Conducted studies showed, that self-hardening’s ability of steel X46Cr13 let obtain technologically usable layered casting characterized by hardness of working surface up to 35 HRC.

14

Wpływ wybranych warunków skrawania na siłę i moment podczas wiercenia żeliwa szarego

Miko E., Nowakowski Ł., Skrzyniarz M.

Mechanik

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2018

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R. 91, nr 8-9

760--762

PL

Przeanalizowano wpływ wybranych parametrów skrawania (prędkości i posuwu) na moment i siłę skrawania podczas wiercenia żeliwa EN-GJL-250. Operacja wiercenia została wykonana wiertłem składanym firmy Allied Machine z serii DEM22000S-20FM, na pionowym centrum frezarskim Hermle B300. Pomiar momentu i siły skrawania podczas wiercenia przeprowadzono siłomierzem firmy Kistler.

EN

The impact of selected cutting parameters (cutting speed and cutting feed) on the torque and cutting force during drilling gray cast iron EN-GJL-250 was analyzed. The drilling operation was carried out by Allied Machnie drill series: DEM22000S-20FM, on the Hermle B300 vertical milling center. The measurement of the torque and the cutting forces during drilling was carried out by Kistler device.

15

Grey Cast Iron Locally Reinforced Using 3D Printing Scaffold Insert

Przyszlak N., Dulska A., Wróbel T., Szajnar J.

Archives of Foundry Engineering

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2018

|

Vol. 18, iss. 1

99--102

EN

The paper presents an innovative method of creating the layered castings. The innovation relies on application the 3D printing insert obtaining in SLM (selective laser melting) method. This type of scaffold insert made from pure Ti powder, was placed into mould cavity directly before pouring by grey cast iron. In result of used method was obtained grey cast iron casting with surface layer reinforced by titanium carbides. In range of studies were carried out metallographic researches using light microscope and scanning electron microscope, microhardness measurements and abrasive wear resistance. On the basis of obtaining results was stated that there is a possibility of reinforcing surface layer of the grey cast iron casting by using 3D printing scaffold insert in the method of mould cavity preparation. Moreover there was a local increase in hardness and abrasive wear resistance in spite of the precipitation of titanium carbides in surface layer of grey cast iron. While the usable properties of composite surface layer obtained in result of use of the method presented in the paper, strongly depend of dimensions of scaffold insert, mainly parameters Re and Ri.

16

Manufacture of two-layer castings using Fe base heat-resistant alloys

Rzepka G., Nawrocki J., Sieniawski J.

Advances in Manufacturing Science and Technology

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2018

|

Vol. 42, nr 1-4

31--41

EN

The main purpose of the present study is to verify the possibility of joining grey iron EN-GJL-250 with heat resistant ductile iron GJS-XSiMo5-1 and heat resistant cast steel GX40CrNiSiNb25-20 to create the two-layered material using casting process with materials in liquid state and in solid state. The mentioned above method was assumed to solve in an economically justified manner the problem of defects on turbocharger’s housing which occurred in some high performance premium application. Evaluation of joint quality was investigated by microstructure observation (LM), alloy elements diffusion (SEM), hardness measurement and discontinuity inspection by computed tomography scanning (CT).

PL

W pracy przedstawiono rezultaty badań określających stopień możliwości wytworzenia połączenia żeliwo szare EN-GJL-250 – żaroodporne żeliwo sferoidalne GJS-XSiMo5-1 lub żaroodporne staliwo GX40CrNiSiNb25-20 w procesie odlewania – materiał w stanie ciekłym i materiał w stanie stałym. Analiza uzyskanych wyników badań wskazuje, że zaproponowana metoda jest ekonomicznie uzasadniona dla rozwiązania występujących wad w obudowie turbosprężarki pojawiających się podczas pracy w warunkach dużej wydajności. Ocenę jakości połączenia prowadzono w badaniach mikrostruktury połączenia (LM i SEM), pomiarach twardości i kontroli nieciągłości przy użyciu tomografii komputerowej (CT).

17

Quality evaluation of iron casting EN-GJL-200 produced on the disamatic line

Boroń K.

Acta Innovations

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2018

|

no. 29

36--40

EN

This article discusses the issues concerning the quality of casting surface with a small unit weight manufactured on the Disamatic automatic casting lines in a flaskless mould with a vertical parting line. The research was conducted in manufacturing conditions in one of the casting facilities in the country. The identification of casting defects for a monthly manufacturing cycle was made and agreed that the main causes of scrap casting are defects on the raw surface: lumps of moulding sand which after removal form cavities and draws as well as defects of gas origin such as blowholes. There are also defects of form namely short runs. In the later part of the work, the research results of the properties of moulding sand were presented and casting defects were selected the occurrence of which is connected with the quality of moulding sands.

18

The properties of cast iron surface layers modified by laser ablation micromachining

Napadłek W., Woźniak A., Pakowski C.

Tribologia

|

2017

|

nr 6

59--64

EN

The article presents the results of model laboratory tests, including the measurement of temperature, friction force, and linear wear of the surface layer of samples made of grey cast iron sliding against a steel counterpart. The surface layer of the cast iron specimen was modified using ablative laser micromachining in order to change its macro- and micro-geometry. To produce regular oil micro-reservoirs in a shape of micro-channels, an Nd: YAG laser (λ = 1064 nm, ƒ = 1 – 100 kHz, E = 50 J, P = 50W) with a special focusing system was used. Comparative studies included a grey cast iron specimen subjected to conventional mechanical machining and a specimen modified by ablative laser micromachining. 41Cr4 steel with a hardness of 50 HRC was used as a counterpart. Tribological tests were run in a pin-on-disk (T-11 tribometer) test set-up. The best results in the reduction of friction, temperature, and wear were obtained for samples with oil micro-reservoirs (made of ablative laser texturing) in a shape of micro-channels covering 5% of the entire tribological contact surface.

PL

W pracy przedstawiono wyniki modelowych badań laboratoryjnych obejmujących pomiary wybranych parametrów w węźle tarcia, tj.: temperatury, siły tarcia i zużycia mierzonego metodą liniową dla warstwy wierzchniej próbek wykonanych z żeliwa szarego w skojarzeniu ze stalowymi przeciwpróbkami. Warstwę wierzchnią ww. żeliwa poddano modyfikacji, wykorzystując ablacyjną mikroobróbkę laserową w celu zmiany jej makroi mikrogeometrii. Do wytworzenia regularnych mikrozasobników olejowych w kształcie mikrokanałów stosowano laser Nd: YAG (λ = 1064 nm, ƒ = 1 ÷ 100 kHz, E = 50 J, P = 50W) ze specjalnym systemem ogniskowania. Badaniom porównawczym poddana została warstwa wierzchnia żeliwa szarego ukształtowana na drodze tradycyjnej obróbki mechanicznej i zmodyfikowana w wyniku ablacyjnej mikroobróbki laserowej. Materiałem przeciwpróbki była stal 41Cr4 o twardości 50 HRC. W badaniach tribologicznych zastosowano metodę „pin-on-disc” w oparciu o tribometr T-11. Najlepsze efekty w zakresie zmniejszenia siły tarcia i temperatury oraz zwiększenia odporności na zużycie uzyskano w przypadku skojarzeń, w których w warstwie wierzchniej żeliwnych próbek wykonano techniką ablacyjnego teksturowania laserowego mikrozbiorniki olejowe w kształcie mikrokanałów z ich 5% udziałem powierzchniowym.

19

Wybrane materiały stosowane w układach hamulcowych i ich właściwości mechaniczne

Szymczak T., Kowalewski Z.

Transport Samochodowy

|

2017

|

z. 2

87--99

PL

W pracy omówiono wybrane materiały stosowane w układach hamulcowych, jak: żeliwo szare, kompozyty ceramiczne oraz metalowe o osnowie ze stopu aluminium. Zaprezentowano ich zasadnicze właściwości mechaniczne oraz parametry fizyczne. Ponadto, omówiono zmiany granicy plastyczności i wytrzymałości doraźnej żeliwa szarego w warunkach rozciągania prowadzonego przy dziewięciu poziomach temperatury w zakresie od 20 °C do 700 °C.

EN

The paper reports selected materials applied in breaking systems, i.e.: grey cast iron, ceramic and metallic composites with aluminium alloy matrix. Their mechanical and physical properties are presented. Variations of the yield point and ultimate tensile strength determined from tensile tests carried out at nine levels of temperature within a range from 20 °C up to 700 °C are discussed.

20

The Effect of a Thin-Wall Casting Mould Cavity Filling Conditions on the Casting Surface Quality

Trytek A., Orłowicz A. W., Tupaj M., Mróz M., Markowska O., Bąk G., Abram T.

Archives of Foundry Engineering

|

2016

|

Vol. 16, iss. 4

222--226

EN

The paper presents results of metallographic examination of faults occurring in the course of founding thin-walled cast-iron castings in furan resin sand molds. A non-conformance of the scab type was Observed on surface of the casting as well as sand buckles and cold shots. Studied the chemical composition by means of a scanning electron microscope in a region of casting defects: microanalysis point and microanalysis surface. Around the observed defects discloses high concentration of oxides of iron, manganese and silicon. A computer simulation of the casting process has been carried out with the objective to establish the cause of occurrence of cold shots on casting surface. The simulation was carried out with the use of NovaFlow & Solid program. We analyzed the flowing metal in the mold cavity. The main reason for the occurrence of casting defects on the surface of the casting was gating system, which caused turbulent flow of metal with a distinctive splash stream of liquid alloy.