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1

Oxide Inclusions in Ductile Cast Iron as Starting Materials for Production SiMo Iron Castings

Dyrlaga Ł., Kopyciński D., Guzik E.

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 3

43--47

EN

This paper presents the study about defects found in industrial high silicon ductile iron. The microstructures were analysed using an optical microscope. Afterwards, a scanning electron microscope was used to analyse the chemical composition. The study also examined the origin of oxygen and what is the amount of oxygen in the cast iron. The amount of active oxygen was measured at two production processes. Firstly, at the end of melting process, and secondly, after the nodularization treatment. The research was carried out with different proportions of the raw materials. The focus was on determining the mechanism of the formation of slag defects to eliminate them in order to obtain ductile iron with increased silicon content of the highest possible quality. The research presented in this publication is a part of an implementation doctorate carried out in the METALPOL Foundry in Węgierska Górka (Poland). The presented research concerns the elaboration of initial parameters of liquid metal intended for processing into high-silicon ductile cast iron SiMo1000 type with aluminum and chromium additives.

2

Innovation technology for the production of massive slag ladles at the Krakodlew S.A. Foundry. Presentation of design works on research and development

Paszkiewicz M., Guzik E., Kopyciński D., Kalandyk B., Burbelko A., Gurgul D., Sobula S., Ziółko A., Piotrowski K., Bednarczyk P.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 4

67--71

EN

This article is a description of the progress of research and development in the area of massive large-scale castings - slag ladles implemented in cooperation with the Faculty of Foundry Engineering of UST in Krakow. Slag ladles are the one of the major castings that has been developed by the Krakodlew (massive castings foundry) for many years. Quality requirements are constantly increasing in relation to the slag ladles. Slag ladles are an integral tool in the logistics of enterprises in the metallurgical industry in the process of well-organized slag management and other by-products and input materials. The need to increase the volume of slag ladles is still growing. Metallurgical production is expected to be achieved in Poland by 2022 at the level of 9.4 million Mg/year for the baseline scenario - 2016 - 9 million Mg/year. This article describes the research work carried out to date in the field of technology for the production of massive slag ladles of ductile cast iron and cast steel.

3

Phase Analysis and Crystallographic Orientation of High Chromium Cast Iron Grain Using EBSD Technique

Siekaniec D., Kopyciński D.

Journal of Casting & Materials Engineering

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2017

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Vol. 1, no. 1

15--19

EN

Grain orientation, properties, microstructure borders, and types and sizes of phases have had a major impact on the traits of modern engineering materials. Therefore, it is important to study, analyze, and (further) control the method of crystallizing alloys. One of the methods used to assess the orientation of grain growth is the EBSD technique. EBSD (Electron Backscatter Diffraction Analysis) enables us to perform quantitative analyses on the microstructure of materials (on a scale of millimetres to nanometres) in a scanning electron microscope. Using the EBSD technique can help us gain valuable information about the following properties of crystalline materials: crystal orientation, disorientation, grain boundaries, global and local texture, fractions recrystallization/deformation, stress analysis, characterization of intergranular boundaries, identification of phases, phase distribution, and so on. In this paper, we present the results of phase analysis and crystallographic orientation of the grains of high chromium cast iron via EBSD. These were preliminary studies to determine the possibility of using the EBSD technique for analyzing high chromium cast iron. Castings were produced under industrial conditions, then samples were cut out and testing using the EBSD technique. This method proved to be effective for this type of material.

4

The Effect of Fe-Ti Inoculation on Solidification, Structure and Mechanical Properties of High Chromium Cast Iron

Kopyciński D., Siekaniec D., Szczęsny A., Guzik E., Nowak A.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 4

2183--2187

EN

The results of studies of the effect of different amounts of the Fe-Ti inoculant on structure and selected mechanical properties of High Chromium Cast Iron (conventionally abbreviated as HCCI) are presented. The main purpose of the inoculation is structure refinement and hence the improvement of casting properties. Generally considered a strong carbide-forming element, titanium is an effective inoculant for the high chromium cast iron. However, there is an optimal amount of titanium addition beyond which the mechanical properties begin to deteriorate. The studies enabled determining the amount of Fe-Ti inoculant optimal for the cast iron of a given chemical composition.

5

Shaping optimal zinc coating on the surface of high-quality ductile iron casting. Part II – Technological formula and value of diffusion coefficient

Kopyciński D., Guzik E., Szczęsny A.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 1

391--395

EN

The completed research presented in the first part of the article has allowed linking the manufacturing technology of ductile iron castings with the process of hot dip galvanizing. On the basis of these data simulations were carried out to examine the behaviour of zinc diffusion coefficient D in the galvanized coating. The adopted model of zinc coating growth helped to explain the cases of excessive growth of the intermetallic phases in this type of coating. The paper analyzes covered the relationship between the roughness and phase composition of the top layer of product and the thickness and kinetics of zinc coating growth referred to individual sub-layers of the intermetallic phases.Roughness and phase composition in the surface layer of product were next related to the diffusion coefficient D examined in respective sublayers of the intermetallic phases.

6

Shaping optimal zinc coating on the surface of high-quality ductile iron casting. Part I – Moulding technologies vs. zinc coating

Szczęsny A., Kopyciński D., Guzik E.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 1

385--390

EN

Studies have demonstrated that in the process of hot dip galvanizing the decisive influence on the mechanism of zinc coating formation and properties has the quality of the mechanically untreated (raw) surface layer of the galvanized product. The terms “casting surface layer” denote various parameters of the microstructure, including the type of metal matrix, the number of grains and the size of graphite nodules, possible presence of hard spots (the precipitates of eutectic cementite) and parameters of the surface condition. The completed research has allowed linking the manufacturing technology of ductile iron castings with the process of hot dip galvanizing.

7

Effect of Titanium Inoculation on Tribological Properties of High Chromium Cast Iron

Siekaniec D., Kopyciński D., Szczęsny A., Guzik E., Tyrała E., Nowak A.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 4

143--146

EN

The present investigation focuses on the study of the influence of titanium inoculation on tribological properties of High Chromium Cast Iron. Studies of tribological properties of High Chromium Cast Iron, in particularly the wear resistance are important because of the special application of this material. High Chromium Cast Iron is widely used for parts that require high wear resistance for example the slurry pumps, brick dies, several pieces of mine drilling equipment, rock machining equipment, and similar ones. Presented research described the effects of various amounts of Fe-Ti as an inoculant for wear resistance. The results of wear resistance were collated with microstructural analysis. The melts were conducted in industrial conditions. The inoculation was carried out on the stream of liquid metal. The following amount of inoculants have been used; 0.17% Fe-Ti, 0.33% Fe-Ti and 0.66% Fe-Ti. The tests were performed on the machine type MAN. The assessment of wear resistance was made on the basis of the weight loss. The experimental results indicate that inoculation improve the wear resistance. In every sample after inoculation the wear resistance was at least 20% higher than the reference sample. The best result, thus the smallest wear loss was achieved for inoculation by 0.66% Fe-Ti. There is the correlation between the changing in microstructure and wear resistance. With greater amount of titanium the microstructure is finer. More fine carbides do not crumbling so quickly from the matrix, improving the wear resistance.

8

Effect of Different Inoculants on Impact Toughness in High Chromium Cast Iron

Siekaniec D., Kopyciński D., Guzik E., Tyrała E., Nowak A.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 2

85--88

EN

The present work, presented the study of effect of different inoculants on impact toughness in High Chromium Cast Iron. The molds were pouring in industrial conditions and samples were tested in laboratory in Faculty of Foundry Engineering at AGH. Seven samples were tested - one reference sample, three with different addition of Fe-Ti, and three with different addition of Al. The samples were subjected to impact toughness on Charpy hammer and the hardness test. The presented investigations indicate that for the each inoculant there is an optimal addition at which the sample obtained the highest value of impact toughness. For the Fe-Ti it is 0.66% and for Al is 0.17%. Of all the examined inoculants best results were obtained at a dose of 0.66% Fe-Ti. Titanium is a well-known as a good modifier but very interesting results gives the aluminum. Comparing the results obtained for the Fe-Ti and Al can be seen that in the case of aluminum hardness is more stable. The hardness of all samples is around 40-45 HRC, which is not high for this type of cast iron. Therefore, in future studies it is planned to carry out the heat treatment procedure that may improves hardness.

9

The Althoff-Radtke Test Adapted for High Chromium Cast Iron

Kopyciński D., Siekaniec D., Szczęsny A., Sokolnicki M., Nowak A.

Archives of Foundry Engineering

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2016

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Vol. 16, iss. 4

61--64

EN

The paper presents results of the possibility of adapting the Althoff-Radtke test for High Chromium Cast Iron. The Althoff-Radtke test is a clump attempt used for steel. The Althoff-Radtke test has four different lengths of clamp which qualifies it as a test to quantitatively take into account different kinds of shrinkage ΔL. The length of the slot of the cracked corner and the length of each staple (50 - 350 mm) are the parameters tendency to cast cracks. Castings of white cast iron have a high tendency to hot cracking due to the large range of solidification temperatures, unfavorable kinetics parameters of shrinkage, and especially a lack of expansion before shrinkage. Shrinkage of high chromium white cast iron is similar to the shrinkage of cast steel, and is approximately 2%. Therefore it is important to test susceptibility to hot cracks. Research was carried out under industrial conditions. Four melts were performed, one of the initial chemical composition and the other three modified by different amounts of Fe-Ti, respectively, 0.25%, 0.5% and 0.75% Fe-Ti. The propensity for hot cracking was based on the observation of the dark surface in the corner of the sample. The study shows that the Althoff-Radtke test can be adapted to determine the tendency for hot cracking of high chromium cast iron. It should however be noted that the test results can not be compared with those for other alloys.

10

Effect of the Surface Layer of Iron Casting on the Growth of Protective Coating During Hot-Dip Galvanizing

Kopyciński D., Guzik E., Szczęsny A.

Archives of Foundry Engineering

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2016

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Vol. 16, iss. 1

25--28

EN

The paper presents the results of investigations of the growth of protective coating on the surface of ductile iron casting during the hot-dip galvanizing treatment. Ductile iron of the EN-GJS-600-3 grade was melted and two moulds made by different technologies were poured to obtain castings with different surface roughness parameters. After the determination of surface roughness, the hot-dip galvanizing treatment was carried out. Based on the results of investigations, the effect of casting surface roughness on the kinetics of the zinc coating growth was evaluated. It was found that surface roughness exerts an important effect on the thickness of produced zinc coating.

11

Sekwencja kształtowania się faz międzymetalicznych w powłoce cynkowej

Kopyciński D.

Inżynieria Materiałowa

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2015

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Vol. 36, nr 5

251--255

PL

W pracy opisano sekwencję kształtowania się struktury powłoki ochronnej podczas cynkowania zanurzeniowego. Natychmiast po zanurzeniu wyrobu w ciekłym cynku tworzy się warstwa stopowa powłoki, składająca się z cząstkowych warstw faz międzymetalicznych Fe–Zn. W początkowym okresie krystalizacji warstwy stopowej na powierzchni wyrobu wprowadzonego do ciekłego cynku powstaje warstwa przechłodzonej cieczy. W wyniku reakcji perytektycznych w warunkach metastabilnych kształtują się poszczególne fazy, tworząc podwarstwy faz w oczekiwanej kolejności: Γ1, δ oraz ζ. Uwalniane ciepło krystalizacji powstających faz międzymetalicznych jest odprowadzane przez cynkowany materiał. Krystalizacja egzogeniczna (kierunkowa) faz międzymetalicznych Fe–Zn wynika z istniejącego gradientu temperatury G, którego przyczynami są między innymi, okresowe „dochodzenie” temperatury ścianki cynkowanego wyrobu do technologicznej temperatury kąpieli cynkowej. W pracy wykazano ponadto, że skład chemiczny podłoża (różne gatunki stali i żeliwo sferoidalne) wpływa na kinetykę wzrostu i budowę warstwy Fe–Zn.

EN

The study describes the sequence of structure formation in a coating during hot galvanizing. Immediately after introducing the galvanized product to a zinc bath, the first to crystallize on its surface is the alloyed layer. It is composed of sublayers of intermetallic phases of Fe–Zn. At the initial stage of crystallization of the alloyed layer on the surface of iron introduced to liquid zinc, a layer of the undercooled liquid is formed. As a result of peritectic reaction under metastable conditions, the individual phases constituting the successive sublayers are forming in the expected sequence of Γ1, δ and ζ. The liberated heat of crystallization of the intermetallic phases in the course of formation is carried away through the galvanized object. The unidirectional crystallization of the intermetallic Fe–Zn phases results from temperature gradient G, an origin of which is to be looked for, among others, in the temperature of the wall of the galvanized element increasing periodically to reach process temperature of the zinc bath. In the study it has been proved, moreover, that the chemical composition of the substrate (different types of steel and ductile iron) affects in a significant manner the growth kinetics and the constitution of Fe–Zn layer.

12

Oddziaływanie warstwy wierzchniej odlewu z żeliwa sferoidalnego na wzrost powłoki cynkowej podczas metalizacji zanurzeniowej

Kopyciński D., Guzik E., Szczęsny A., Siekaniec D.

Inżynieria Materiałowa

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2015

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Vol. 36, nr 2

65--68

PL

W pracy zawarto wyniki badań powłoki ochronnej ukształtowanej podczas zabiegu cynkowania zanurzeniowego na powierzchni wyrobu z żeliwa sferoidalnego. Wytop żeliwa sferoidalnego gatunku EN-GJS-600-3 został przeprowadzony w warunkach przemysłowych, natomiast formy odlewnicze wykonano w warunkach przemysłowych i laboratoryjnych w celu uzyskania zróżnicowanego parametru chropowatości powierzchni analizowanych odlewów, który został określony za pomocą profilometru. Zabieg cynkowania zanurzeniowego przeprowadzono na stanowisku laboratoryjnym w Pracowni Inżynierii Powierzchni Odlewów w Katedrze Inżynierii Stopów i Kompozytów Odlewanych na Wydziale Odlewnictwa AGH w Krakowie. Na podstawie przeprowadzonych badań dokonano oceny wpływu chropowatości powierzchni odlewu na kinetykę wzrostu powłoki cynkowej. Stwierdzono, że chropowatość powierzchni ma istotny wpływ na grubość powstającej powłoki cynkowej.

EN

In terms of economically and ecologically hot dip galvanizing Fe–C alloys is one of the best ways of protecting ferrous alloys from the destructive effects of atmospheric corrosion. The article contains the results of the protective coating formed during hot dip galvanizing treatment on the surface of a ductile cast iron. Melting of cast iron EN-GJS-600-3 grade was carried out in industrial conditions, while the molds were made in industrial and laboratory conditions to obtain varied surface roughness parameter of castings, which has been tested on a profilometer. Hot dip galvanizing was performed in Laboratory of the Engineering of Casting Surface, Department of Engineering of Cast Alloys and Composites. Based on the performed studies assesses the impact of the obtained surface roughness of castings on the kinetics of growth of the zinc coating. It was found that the surface roughness has a significant impact on the thickness of the zinc coating.

13

Growth Law For Peritectic Phases Formation In The Zinc Coating

Guzik E., Kopyciński D., Wołczyński W.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 3

2335-2340

EN

Some experiments dealing with the isothermal hot dip galvanizing were carried out. The (Zn) – coating settled on the Armco-iron substrate were examined after arresting the solidification for different periods of time. The measurement of the thickness of each sub-layer in the coating were performed due to the SEM – analysis. The zinc segregation on the cross-section of the studied sub-layers were also determined by the EDS technique. The growth laws are formulated mathematically for each of the observed sub-layer. The mechanism of the sub-layer formation is also analysed due to the observation of the birth/nucleation of the phases in the sub-layers and the effect of flux onto the sub-layers morphology formation. The appearance of each phase is referred to the Fe-Zn diagram for stable equilibrium according to which these phases are the products of the adequate peritectic transformation.

PL

Przeprowadzono eksperymenty izotermicznego cynkowania zanurzeniowego. Powłoka (Zn) osadzona na żelazie Armco poddana została badaniom po zatrzymaniu krystalizacji dla różnych czasów trwania cynkowania. Dokonano pomiarów grubości każdej z podwarstw powłoki dzięki analizie SEM. Segregacja cynku na przekroju badanych podwarstw również została określona dzięki pomiarom przy użyciu techniki EDS. Sformułowane są matematycznie prawa wzrostu dla każdej z analizowanych podwarstw. Analizowany jest również mechanizm kształtowania podwarstw dzięki obserwacjom narodzin/zarodkowania poszczególnych faz w podwarstwach oraz dzięki analizie oddziaływania topnika na morfologię podwarstw. Formowanie każdej z faz jest odniesione do diagramu równowagowego Fe-Zn zgodnie z którym fazy te są produktami odpowiednich reakcji perytektycznych.

14

Flux Effect Onto Peritectic Phases Growth In The Zinc Coating

Kopyciński D., Guzik E.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 3

2341--2346

EN

A model of the (Zn) – coating formation on the iron/steel substrate is proposed. The model assumes the phases’ sub-layers creation in a sequence. This sequence is referred to the Fe-Zn phase diagram. However, this sequence of phases’ appearance is perturbed by the flux presence in the zinc bath. The flux effect on the coating morphology and appearance/disappearing of some sub-layers is analysed. The phases’ formation is treated as the result of the peritectic reaction accompanying the coating solidification. A comparison of the coating formations before and after flux decay is delivered. Thus, a function which describes the flux decay is also analysed. Additionally, a ternary Fe-Zn-F(flux) phase diagram is considered. The varying zinc concentration across the phases sub-layers is described with the use of the function which determines the flux decay. The behaviour of the solidification path before and after flux decay is discussed due to the adequate equations formulated in frame of the current model.

PL

Zaproponowany został model kształtowania się powłoki (Zn) na podłożu ze stali/żelaza. Model zakłada powstawanie podwarstw faz w pewnej sekwencji. Sekwencja ta odniesiona jest do diagramu równowagowego. Jednak, sekwencja ta zakłócona jest obecnością topnika w kąpieli. Wpływ topnika na morfologię powłoki oraz na pojawianie się/zanik niektórych podwarstw jest analizowany. Powstawanie faz traktowane jest jako rezultat reakcji perytektycznych towarzyszących krystalizacji powłoki. Pokazane jest porównanie kształtowania się powłoki przed i po zaniku topnika. Stąd, analizowana jest również funkcja, która opisuje zanik topnika. Dodatkowo, rozważany jest potrójny diagram fazowy Fe-Zn-topnik. Zmienne stężenie cynku na grubości podwarstw opisane jest z użyciem funkcji, która opisuje zanik topnika. Zachowanie się ścieżki krystalizacji przed i po zaniku topnika jest dyskutowane w odniesieniu do stosownych równań sformułowanych w proponowanym modelu.

15

The Effect of Addition of Titanium on The Structure and Properties of High Chromium Cast Iron

Kopyciński D., Guzik E., Siekaniec D., Szczęsny A.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 3

35--38

EN

The paper presents results of Ti-addition to High Chromium Cast Iron (HCCI) on the structure and selected mechanical properties. For this study casted two sets of cylinders with dimensions ø20 mm, ø15 mm x 250 mm, for the High Chromium Cast Iron (HCCI) and with the 4% by mass Ti-addition. Melts were performed in the induction furnace crucible capacity of 15 kg. During the heats the cup with installed S type thermocouple was poured to record the cooling curves. The cylinders were subjected to the static bending strength test. Samples for the test microstructure and Rockwell hardness were cut from the cylinders. The study shows that the addition of titanium had an impact on the structure and thus the properties of High Chromium Cast Iron (HCCI). In subsequent studies, through an appropriate choice of chemical composition and proper process control, it is planned to obtain in the structure the titanium carbides TiC and chromium carbides with type (Cr, Fe)7C3.

16

Przykład obróbki cieplnej odlewów z żeliwa wysokochromowego

Siekaniec D., Szczęsny A., Kopyciński D.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 4 spec.

109--112

PL

Żeliwo wysokochromowe jest powszechnie stosowanym materiałem w przemyśle górniczym i mineralnym, gdzie wymagana jest duża odporność na zużycie ścierne. Swoje dobre właściwości zawdzięcza obecności w mikrostrukturze twardych węglików. Żeliwo chromowe poddawane hartowaniu ma w praktyce osnowę austenityczną, austenityczno-perlityczną lub perlityczną. Istotnym procesem w czasie obróbki cieplnej jest tzw. destabilizacja austenitu, jest on ważny ponieważ dopiero po jego zajściu może nastąpić przemiana martenzytyczna. W zależności od szybkości chłodzenia, które następuje po procesie destabilizacji austenitu, może powstać perlit, bainit i martenzyt. Przeprowadzone badania dotyczyły określenia wpływu szybkości chłodzenia odlewów z żeliwa wysokochromowego po obróbce cieplnej, na mikrostrukturę i twardość. Badaniu zostało poddane żeliwo wysokochromowe o zawartości 27%Cr i 2,7%C. Przeprowadzono zabieg hartowania z temperatury 950 °C w czasie 4h, następnie odlewy poddano trzem wariantom chłodzenia – w wodzie, w kąpieli solnej i na powietrzu. Zbadano i porównano mikrostrukturę oraz twardość odlewów dla różnych wariantów chłodzenia.

EN

High Chromium Cast Iron (HCCI) is widely use in mining and mineral industry, where abrasive resistance is a principal requirement. Its good properties thanks to the hard eutectic carbides occurring in the microstructure. The effect of heat treatment on HCCI was a subject of many research. High Chromium Cast Iron have an austenitic, austenitic-pearlitic or pearlitic matrix. An important process during the heat treatment is austenite destabilization, thus until after it conduct the martensitic transformation can occur. Depending on the cooling rate that follows the process of destabilization of austenite, perlite, bainite and martensite may form. The present work, aimed at studying the influence of cooling rate after heat treatment, on the microstructure and hardness. The study were carry out on samples of High Chromium Cast Iron containing 27%Cr i 2,7%C. Samples were subjected to the tempering treatment at the temperature of 950°C for 4 hours and three variants of cooling – in water, in a salt bath and on air. Examined and compared the microstructure and hardness of castings for different variants of cooling.

17

Kinetyka wzrostu powłoki ochronnej podczas wysoko- i niskotemperaturowego cynkowania zanurzeniowego odlewów z żeliwa sferoidalnego

Kopyciński D., Guzik E., Szczęsny A., Siekaniec D.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 2 spec.

47--50

PL

W pracy przedstawiono porównanie mikrostruktury powłoki cynkowej otrzymanej na powierzchni odlewu z żeliwa sferoidalnego gatunku EN-GJS-5007 podczas zabiegu cynkowania zanurzeniowego w procesie „niskotemperaturowym” 450°C oraz „wysokotemperaturowym” 580°C. Zbadano kinetykę wzrostu powłoki cynkowej, zidentyfikowano wzrastające fazy Fe-Zn oraz występowanie wydzieleń „twardego cynku” w powłoce.

EN

The paper presents a comparison of the zinc coating microstructure obtained on EN-GJS-500-7 grade ductile cast iron surface during the hot dip galvanizing in the "low temperature" 450 °C and "high temperature" 580 °C. The kinetics of growth of the zinc coating was investigated. The phases of Fe-Zn and the presence of precipitates "hard zinc" in the coating have been identified.

18

Diffusion Coefficient in the Zinc Coating Shaped on the Surface of Cast Iron and Steel Alloys

Kopyciński D., Guzik E., Szczęsny A., Siekaniec D.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 2

43--46

EN

The article presents the method to assess the diffusion coefficient D in the sub-layer of intermetallic phases formed during hot-dip galvanizing “Armco” iron and ductile cast iron EN-GJS-500-7. Hot-dip galvanizing is one of the most popular forms of long-term protection of Fe-C alloys against corrosion. The process for producing a protective layer of sufficient quality is closely related to diffusion of atoms of zinc and iron. The simulation consist in performed a hot-dip galvanizing in laboratory condition above Fe-C alloys, in the Department of Engineering of Cast Alloys and Composites. Galvanizing time ranged from 15 to 300 seconds. Then metallographic specimens were prepared, intermetallic layers were measured and diffusion coefficient (D) were calculated. It was found that the diffusion coefficient obtained during hot-dip galvanizing “Armco” iron and zinc is about two orders of magnitude less than the coefficient obtained on ductile cast iron EN-GJS-500-7.

19

Wpływ ziaren austenitu pierwotnego na mikrostrukturę i właściwości mechaniczne modyfikowanego żeliwa z grafitem płatkowym

Kopyciński D., Guzik E., Szczęsny A., Dorula J.

Przegląd Odlewnictwa

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2014

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Vol. 64, nr 11-12

456--462

PL

Prowadzone badania wykazują, że wprowadzenie sproszkowanego żelaza do wytapianego żeliwa o niskiej zawartości siarki przed zabiegiem modyfikacji prowadzonej konwencjonalnym modyfikatorem grafityzującym pozwala na uzyskanie właściwości mechanicznych zbliżonych do wartości uzyskiwanych w trakcie modyfikacji żeliwa o podwyższonej zawartości siarki. Prowadzony zabieg powoduje wzrost liczby zarodków krystalizacji dendrytów austenitu pierwotnego. W tym przypadku, cząsteczki sproszkowanego żelaza działają, jako substraty dla zarodkowania austenitu pierwotnego, podobnie do zachowania się sieci regularnej siatki krystalograficznej. Zwiększona liczba dendrytów austenitu pierwotnego powoduje zmniejszenie się przestrzeni międzydendrytycznych utrudniając tym samym tworzenie się ziaren eutektycznych, czego efektem jest wzrost właściwości mechanicznych.

EN

The study proves that by introducing the iron powder to low-sulphur cast iron still before the inoculation carried out with a conventional graphitising inoculant, the mechanical properties similar to those obtained during the inoculation treatment carried out on cast iron with the recommended high sulphur content are achieved. The said operation increases the number of crystallisation nuclei of the primary austenite dendrites. In this case, the iron particles act as substrates for the nucleation of primary austenite due to a similar crystallographic behaviour of the regular face cantered cubic lattice. The more numerous are the dendrites of primary austenite, the less free space is available in the interdendritic spaces for the formation of graphite eutectic grains, which makes the mechanical properties higher.

20

Solidification of Fe-Zn sublayers during galvanizing process

Kopyciński D., Guzik E., Wołczyński W.

Inżynieria Materiałowa

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2014

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Vol. 35, nr 2

158--161

EN

The study describes the mechanism of structure formation in protective coating, growing on iron surface during hot-dip galvanizing. As a first stage of the galvanizing process, immediately after the iron sample has been dipped in galvanizing bath, a layer of frozen zinc is crystallizing on the sample surface. Next, as a result of isothermal solidification, an alloyed layer of the coating; composed of the sublayers of intermetallic Fe-Zn phases, is formed. At the initial stage of the existence of the alloyed layer, another layer, that of undercooled liquid, is formed on the surface of iron dipped in liquid zinc. As a result of peritectic reactions under metastable conditions, the individual phases are born, forming sublayers in the expected sequence of Γ1, δ and ζ.

PL

W pracy opisano mechanizm kształtowania się struktury powłoki ochronnej podczas cynkowania zanurzeniowego. Podczas pierwszego etapu procesu, zaraz po zanurzeniu wyrobu w ciekłym cynku, w pierwszej tworzy się na jego powierzchni kolejności warstwa namrożonego cynku. Warstwa ta roztapia się po pewnym czasie. Następnie w wyniku krystalizacji izotermicznej tworzy się warstwa stopowa powłoki, składająca się z cząstkowych warstw faz międzymetalicznych Fe-Zn. W początkowym okresie krystalizacji warstwy stopowej na powierzchni wyrobu wprowadzonego do ciekłego cynku powstaje warstwa przechłodzonej cieczy. W wyniku reakcji perytektycznych w warunkach metastabilnych kształtują się poszczególne fazy, tworząc podwarstwy faz w oczekiwanej kolejności: Γ1, δ oraz ζ.