BazTech - Yadda

1

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.

2

Prediction of Selected Mechanical Properties in Austempered Ductile Iron with Different Wall Thickness by the Decision Support Systems

Jaśkowiec Krzysztof, Opaliński Andrzej, Kustra Piotr, Jach D., Wilk-Kołodziejczyk Dorota

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 2

137--144

EN

The structure of Austempered Ductile Iron (ADI) is depend of many factors at individual stages of casting production. There is a rich literature documenting research on the relationship between heat treatment and the resulting microstructure of cast alloy. A significant amount of research is conducted towards the use of IT tools for indications production parameters for thin-walled castings, allowing for the selection of selected process parameters in order to obtain the expected properties. At the same time, the selection of these parameters should make it possible to obtain as few defects as possible. The input parameters of the solver is chemical composition Determined by the previous system module. Target wall thickness and HB of the product determined by the user. The method used to implement the solver is the method of Particle Swarm Optimization (PSO). The developed IT tool was used to determine the parameters of heat treatment, which will ensure obtaining the expected value for hardness. In the first stage, the ADI cast iron heat treatment parameters proposed by the expert were used, in the next part of the experiment, the settings proposed by the system were used. Used of the proposed IT tool, it was possible to reduce the number of deficiencies by 3%. The use of the solver in the case of castings with a wall thickness of 25 mm and 41 mm allowed to indication of process parameters allowing to obtain minimum mechanical properties in accordance with the PN-EN 1564:2012 standard. The results obtained by the solver for the selected parameters were verified. The indicated parameters were used to conduct experimental research. The tests obtained as a result of the physical experiment are convergent with the data from the solver.

3

Evaluation of the Phases Present in the Zinc Coating Obtained on the Ductile Cast Iron Substrate in the Bath with the Addition of Ti

Bracka-Kęsek Karolina, Szczęsny Andrzej, Kopyciński Dariusz, Guzik Edward

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 4

5--13

EN

This paper presents the effect of the addition of Ti to the zinc bath. Hot-Dip Galvanizing was carried out on a machined ductile cast iron substrate. The process was carried out at 550°C. Experimental baths A, B and C contained 0.01%, 0.05% and 0.1%Ti, respectively. Metallographic samples were prepared to reveal the microstructure of the coatings. Thickness measurements of the obtained coatings were carried out, and graphs of the approximate crystallization kinetics of the zinc coating were prepared. High-temperature galvanization carried out on the treated surface led to the release of graphite beads from the metal matrix and their diffusion into the coating. This phenomenon can have an adverse effect on the continuity of the coating and its adhesion to the substrate. Crystallization of the δ phase was observed in the coating, and at longer immersion times – a mixture of two-phase δ1 and η phases. With increasing Ti content in the bath, a deterioration in the casting properties of the bath was observed.

4

Difficulties in the Production of Ausferritic Nodular Cast Iron without Heat Treatment

Stawarz Marcin, Lenert Małgorzata, Piasecki Karol

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 3

5--11

EN

The paper presents results of tests carried out on ausferrite carbide matrix alloyed ductile cast iron. The ausferrite was obtained via addition of Cu and Mo alloying elements. This eliminated heat treatment from the alloy production cycle. The article presents results of tests of the quality of the obtained material. Emphasis was put on metallographic analysis using light and scanning microscopy. Works also included chemical composition tests and EDS analysis. Strength tests were executed in an accredited laboratory. It is possible to create a raw ausferrite carbide matrix without subjecting an alloy to heat treatment. However, it turned out that quality parameters of cast iron were insufficient. The obtained material hardness was 515 HB, while Rm strength and A5 ductility were very low. The low tensile strength of the analyzed alloy resulted from the presence of degenerate graphite secretion (of flake or vermicular shape) in the cast iron. The tests also demonstrated that the alloy was prone to shrinkage-related porosity, which further weakened the material. Alloys made of alloyed ductile iron of ausferrite matrix micro-structure are very attractive due to elimination of the heat treatment process. However, their production process and chemical composition must be optimized.

5

Kierunek minimalizacji powstania odpadów podczas budowy sieci wodociągowej i kanalizacyjnej

Nerkowski Mateusz

Gaz, Woda i Technika Sanitarna

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2022

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Nr 7-8

23--32

PL

Praca obejmuje analizę możliwości wykorzystania rur wodociągowych i kanalizacyjnych pozostałych po wybudowaniu odcinka sieci, pod kątem gospodarki obiegu zamkniętego. Przenalizowano materiały używane do budowy: • wodociągu: żeliwo sferoidalne oraz polietylen, • kanalizacji: kamionka oraz poliwęglan. Na podstawie projektów istniejących już sieci na terenie Warszawy ustalono, jaka ilość materiału pozostanie po wybudowania rurociągu z danego materiału oraz w jaki sposób można wykorzystać materiał pozostały po budowie w ramach GOZ. Przenalizowano możliwość wykorzystania materiału w branży budowlanej oraz zweryfikowano zastosowanie biorąc pod uwagę w szerszym aspekcie gospodarki.

EN

The work includes an analysis of the possibility of using water and sewage pipes remaining after the construction of a network section, in terms of a closed-loop economy. The analysed materials used for the construction were: • water mains: ductile cast iron and polyethylene, • sewerage: stoneware and polycarbonate. Based on designs of existing networks in Warsaw, it was determined how much material would remain after a pipeline was built using a given material and how the material remaining after construction could be used within the framework of GOZ. The possibility of using the material in the construction industry was analysed and its application in a wider aspect of the economy was verified.

6

Effect of Inoculants on the Structure and Properties of Thin-Walled Ductile Iron Castings

Roučka Jaromir, Kaňa Václav, Kryštůfek T., Chýlková A.

Archives of Foundry Engineering

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2022

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Vol. 22, iss. 4

90--95

EN

In many application fields, thin-walled ductile iron castings can compete with castings made from aluminium alloys thanks as their show superior mechanical properties higher stiffness, vibrations damping as well as properties at higher temperatures. As problematic criterion in thin-walled cast-iron castings can be seen the graphitization ability and high sensitivity of the structure and the mechanical properties to the solidification rate. The tests were curried on plate castings with wall thicknesses of 3, 5, and 8 mm, using inoculants based on FeSi70 with different contents of nucleation-active elements as aluminium, calcium, zirconium and magnesium. The inoculation was made by the in-mould method. In the experiments structures were achieved, differing by the graphite dispersity, structure and mechanical properties. The experiments have proved particularly a high sensitivity of the structure and the mechanical properties to the cooling rate of the sample castings. The influence of the inoculant type is less important than the influence of solidification rate.

7

Comparison of the Classical Algorithm with the Training Algorithm in Scheduling Problem ADI Production

Wilk-Kołodziejczyk D., Chrzan K., Jaśkowiec K., Pirowski Z., Żuczek R., Bitka A., Machulec D.

Archives of Foundry Engineering

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2022

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Vol. 22, iss. 1

5--12

EN

A classical algorithm Tabu Search was compared with Q Learning (named learning) with regards to the scheduling problems in the Austempered Ductile Iron (ADI) manufacturing process. The first part comprised of a review of the literature concerning scheduling problems, machine learning and the ADI manufacturing process. Based on this, a simplified scheme of ADI production line was created, which a scheduling problem was described for. Moreover, a classic and training algorithm that is best suited to solve this scheduling problem was selected. In the second part, was made an implementation of chosen algorithms in Python programming language and the results were discussed. The most optimal algorithm to solve this problem was identified. In the end, all tests and their results for this project were presented.

8

Assessment of the Quality of Ductile Cast Iron EN-GJS-500-7 Through the Influence of its Chemical Composition on the Grain Composition of Spheroidal Graphite

Pacha-Gołębiowska Halina

Archives of Foundry Engineering

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2022

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Vol. 22, iss. 4

85--89

EN

Quantitative evaluation of the microstructure obtained in a product is nowadays commonly required both in R&D activities and during routine quality control of materials and components. This paper presents an assessment of the quality of ductile cast iron, based on investigations of the effect of chemical composition on the distribution of ductile graphite precipitates in low-alloy cast iron EN-GJS-500-7. The size of graphite precipitates was expressed in terms of equivalent cross-sectional diameter, which made it possible to describe the distribution of graphite precipitates with a function simulating the log-normal distribution of graphite. The resulting U, W and Z parameters were statistically analysed, including the effect of chemical composition on graphite distribution. In the studied cast iron, the components that increase the U parameter are silicon, manganese and phosphorus, thus favourably affecting the total graphite number. In contrast, the constituents that decrease the U parameter are carbon, chromium and aluminium.

9

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.

10

Artificial Intelligence Approaches to Determine Graphite Nodularity in Ductile Iron

Brait Maximilian, Koppensteiner Eduard, Schindelbacher Gerhard, Li Jiehua, Schumacher Peter

Journal of Casting & Materials Engineering

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2021

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Vol. 5, no. 4

94--102

EN

The complex metallurgical interrelationships in the production of ductile cast iron can lead to enormous diﬀerences in graphite formation and local microstructure by small variations during production. Artiﬁcial intelligence algorithms were used to describe graphite formation, which is inﬂuenced by a variety of metallurgical parameters. Moreover, complex physical relationships in the formation of graphite morphology are also controlled by boundary conditions of processing, the eﬀect of which can hardly be assessed in everyday foundry operations. The inﬂuence of relevant input parameters can be predetermined using artiﬁcial intelligence based on conditions and patterns that occur simultaneously. By predicting the local graphite formation, measures to stabilise production were deﬁned and thereby the accuracy of structure simulations improved. In course of this work, the most important dominating variables, from initial charging to ﬁnal casting, were compiled and analysed with the help of statistical regression methods to predict the nodularity of graphite spheres. We compared the accuracy of the prediction by using Linear Regression, Gaussian Process Regression, Regression Trees, Boosted Trees, Support Vector Machines, Shallow Neural Networks and Deep Neural Networks. As input parameters we used 45 characteristics of the production process consisting of the basic information including the composition of the charge, the overheating time, the type of melting vessel, the type of the inoculant, the fading, and the solidification time. Additionally, the data of several thermal analysis, oxygen activity measurements and the final chemical analysis were included. Initial programme designs using machine learning algorithms based on neural networks achieved encouraging results. To improve the degree of accuracy, this algorithm was subsequently adapted and reﬁned for the nodularity of graphite.

11

Microstructural tests and hardness tests of surface layers of nodular cast iron GJS-350 made using the laser surface alloying process

Sacha Denis

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2021

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Vol. 65, No. 6

37--45

EN

The article presents test results concerning the microstructure and the hardness of a composite layer made on a substrate of nodular cast iron GJS-350 using the laser surface alloying method. The alloying agent used in the test was powdered titanium. The study consists of an overview of reference publications aimed to introduce the most important aspects concerning the issue subjected to analysis. The research part presents the methodology of tests as well as their results and analysis. Microscopic analysis revealed that the layer structure was fine-grained and highly homogenous, whereas hardness measurements revealed that the titanium-enriched layer was characterised by significantly higher micro-hardness than that of the base material.

PL

Artykuł przedstawia wyniki badań mikrostruktury i twardości wytworzonej warstwy kompozytowej na podłożu z żeliwa sferoidalnego GJS-350 metodą stopowania laserowego. Jako dodatku stopującego użyto tytanu w postaci proszku. Praca składa się z przeglądu literatury, który ma przybliżyć najważniejsze zagadnienia dotyczące analizowanego problemu. W części badawczej przedstawiono metodologię prowadzonych badań naukowych oraz uzyskane wyniki i ich analizę. Przeprowadzona analiza mikroskopowa pozwoliła ustalić, że wytworzona warstwa ma drobnoziarnistą strukturę o wysokiej jednorodności. Natomiast badania twardości potwierdziły, że warstwa wzbogacona w dodatek tytanu wykazuje znacznie wyższą mikrotwardość niż materiał podłoża.

12

The Influence of Final Inoculation on the Metallurgical Quality of Nodular Cast Iron

Dwulat Rafał, Janerka K., Grzesiak K.

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 4

5--14

EN

The article presents the results of research on the physicochemical and mechanical properties, microstructure, and the tendency to form shrinkage of nodular cast iron depending on the type of inoculant used for secondary inoculation. Six different inoculants containing different active elements in their chemical composition were used for the research. Step castings and Y2 wedges were made on the vertical forming line using an automatic pouring machine. The inoculation in the amount of 0.2% was made using a pneumatic dispenser equipped with a vision system controlling the effectiveness of the inoculation. The results of the thermal analysis were determined and compared, and the potential of each of the inoculants was assessed.

13

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.

14

Guidelines for the manufacture of heavy ductile iron castings

Rączka Marek, Pysz Stanisław, Piotrowski Krzysztof

Technical Transactions

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2020

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Vol. 117, iss. 1

art. no. e2020044

EN

This study is devoted to the analysis of the impact that the basic constituents of ductile iron (carbon and silicon) and spheroidising treatment combined with inoculation exert on the final properties of heavy ductile iron castings. To evaluate the possibility of the application of ductile iron technology in the manufacture of castings for wind power plants, simulations were conducted on cast hubs of the rotor blades for wind turbines. For this type of product, it is necessary to produce castings characterised by a ferritic matrix (over 90% ferrite) and to reduce the amount of pearlite and graphite to a minimum, both of which are considered as the main structural constituents that affect the casting properties. The key guidelines for the manufacture of heavy castings from ductile iron, wind turbines included, were discussed, with particular emphasis placed on the process of spheroidising treatment and inoculation, both of which are aimed at producing in the structure of castings a spheroidal graphite of a size from 5 to 12 mm (class V to VI) and a ferritic structure in an amount exceeding 90%. This article is the result of the work done by Krakodlew S.A to implement research project No. POIG 01.04.00-12-116/12, supported by the National Centre for Research and Development and financed by the European Regional Development Fund, measure 1.4 POIG (Execution of industrial research and development in the company Krakodlew S.A., 2014).

PL

W pracy przedstawiono analizę zarówno wpływu podstawowych pierwiastków żeliwa sferoidalnego, takich jak węgiel i krzem, jak i procesów sferoidyzacji oraz modyfikacji na końcowe właściwości ciężkich odlewów z żeliwa sferoidalnego. Do oceny możliwości wykorzystania technologii do wykonywania odlewów w energetyce wiatrowej przeprowadzono badania symulacyjne odlewu piasty śmigła wirnika w elektrowni wiatrowej. Dla tego typu wyrobów zachodzi konieczność otrzymania odlewów o strukturze ferrytycznej (powyżej 90% ferrytu) i ograniczenia do minimum ilości perlitu oraz grafitu jako kluczowych składników strukturalnych mających wpływ na właściwości odlewów. Omówiono założenia wykonywania ciężkich odlewów z żeliwa sferoidalnego, w tym dla elektrowni wiatrowych, ze szczególnym uwzględnieniem procesów sferoidyzacji i modyfikacji, które mają zmierzać do osiągnięcia w strukturze odlewu grafitu kulkowego o wymiarach 5 do 12 mm (klasa V do VI) oraz struktury ferrytycznej powyżej 90%. Artykuł powstał w wyniku realizacji przez Krakodlew S.A. projektu badawczego nr POIG 01.04.00-12-116/12, objętego wsparciem Narodowego Centrum Badań i Rozwoju, finansowanego ze środków Europejskiego Funduszu Rozwoju Regionalnego, działanie 1.4 POIG.

15

Corrosion resistance of SiMo- and SiCu-types of nodular cast iron in NaCl solution

Vaško Alan, Zatkalíková Viera, Kaňa Václav

System Safety : Human - Technical Facility - Environment

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2020

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Vol. 2, nr 1

191--198

EN

Nodular cast irons are used in a wide range of industrial applications, especially in the automotive industry. SiMo-type of nodular cast iron is suitable for high-temperature applications, for example the exhaust manifolds of the combustion engines; SiCu-type of nodular cast iron is used in various components of tribotechnical units. These automotive components often work in a corrosive environment. Therefore, the aim of this paper is to compare the corrosion resistance of two types of the nodular cast irons (SiMo-type and SiCu-type). Corrosion resistance was determined by the exposure immersion test at ambient temperature. Specimens of both types of nodular cast iron were immersed in 3.5 % NaCl solution (to simulate sea water) and gradually removed from the solution after 1, 2, 4 and 8 weeks. Subsequently, the weight loss (g) and the average corrosion rate (g m-2 day-1) were calculated. Experimental results show that nodular cast iron alloyed by Si and Mo has higher corrosion resistance than the nodular cast iron alloyed with Si and Cu. Moreover, the mechanical properties (evaluated by tensile test, impact bending test and hardness test) and fatigue properties of both types of nodular cast iron has been compared in the paper.

16

Protective properties of a multi-layer external coating applied to underground pipes of ductile iron

Kochmańska Agnieszka, Wassilkowska Anna, Dąbrowski Wojciech

Instal

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2020

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nr 8

29--32

EN

In this work the analysis of corrosion for ductile iron pipes with diameters of 350 and 500 mm was performed. Two phenomena regarding the pipes coating deterioration have been recognized: corrosion and abrasion. The corrosion tests performed on different coatings in a neutral salt spray for up to 1000 hours indicate that this method is applicable for a rough external surface of centrifugally casted ductile iron pipes. The abrasion tests have been performed manually, using a grinding paper 1000#, due to an irregular profile of the external pipe surface transferred from the casting mold. It helped to obtain “spotted” sections, which were further microscopically analyzed (layer-by-layer). The last procedure, however not standardized, could be in some regards more convenient comparing to traditional cross-sections.

PL

W pracy dokonano analizy korozji rur z żeliwa sferoidalnego o średnicach 350 i 500 mm. Wykryto dwa zjawiska związane z pogorszeniem się powłoki rur: korozja i ścieranie. Testy korozyjne przeprowadzone na różnych powłokach w neutralnej mgle solnej przez okres do 1000 godzin wskazują, że metoda ta ma zastosowanie do szorstkiej zewnętrznej powierzchni odlewanych wirowo rur z żeliwa sferoidalnego. Testy na ścieranie przeprowadzono ręcznie przy użyciu papieru ściernego 1000 #, ze względu na nieregularny profil zewnętrznej powierzchni rury przeniesionej z formy odlewniczej. Pomogło to w uzyskaniu „plamkowych” przekrojów, które poddano dalszej analizie mikroskopowej (warstwa po warstwie). Ostatnia procedura, choć nie znormalizowana, może być pod pewnymi względami wygodniejsza w porównaniu do tradycyjnych przekrojów poprzecznych.

17

The Influence of Selected Melting Parameters on the Physical and Chemical Properties of Cast Iron

Petrus Ł., Bulanowski A., Kołakowski J., Brzeżański M., Urbanowicz M., Sobieraj J., Matuszkiewicz G., Szwalbe L., Janerka K.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 1

105--110

EN

This paper presents the problems related to smelting gray and ductile cast iron. Special attention is paid to the metallurgical quality of cast iron. It depends on the type of furnace, charge materials and the special combination of charge, overheating and holding temperature, melting time, modification and spheroidization method. The evaluation of metallurgical quality has been performed by using derivative-thermal analysis (DTA). During the smelting process and secondary metallurgy, the ITACA system was used allowing to obtain information on alloy characteristic temperatures (Tliquidus, TeMin, TeMax, Tsolidus), VPS value, recalescence value, IGQ coefficient, nucleation gauge, porosity etc. The results of investigations and calculations are displayed in the form of graphs and dependencies. It has been shown that the derivative-thermal analysis (DTA) is an effective complement of chemical analysis and it has been found that both the increase in temperature and metal holding time have a negative impact on the metallurgical quality of liquid metal. The metallurgical quality can be improved by using proper composition of charge materials and modifiers.

18

Solid Particle Erosion of Laser Surface Melted Ductile Cast Iron

Kotarska A., Janicki D., Górka J., Poloczek T.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 3

105--111

EN

The article presents research on solid particle erosive wear resistance of ductile cast iron after laser surface melting. This surface treatment technology enables improvement of wear resistance of ductile cast iron surface. For the test ductile cast iron EN GJS-350-22 surface was processed by high power diode laser HPDL Rofin Sinar DL020. For the research single pass and multi pass laser melted surface layers were made. The macrostructure and microstructure of multi pass surface layers were analysed. The Vickers microhardness tests were proceeded for single pass and multi pass surface layers. The solid particle erosive test according to standard ASTM G76 – 04 with 30°, 60° and 90° impact angle was made for each multi pass surface layer. As a reference material in erosive test, base material EN GJS-350-22 was used. After the erosive test, worn surfaces observations were carried out on the Scanning Electron Microscope. Laser surface melting process of tested ductile cast iron resulted in maximum 3.7 times hardness increase caused by microstructure change. This caused the increase of erosive resistance in comparison to the base material.

19

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.

20

Electrochemical Corrosion Evaluation of Copper-Alloyed Ductile Cast Irons

Brito P., Pereira W., Santos W., Gomes H.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 2

26--30

EN

In the present work, different Cu-alloyed model ductile irons with ferritic (0%Cu-0.09%Mn), mixed ferritic-pearlitic (0.38%Cu-0.40%Mn) and pearlitic (0.69%Cu-0.63%Mn) microstructure were produced and analyzed in terms of their electrochemical corrosion behavior in a 3.5wt.%NaCl aqueous solution containing naturally dissolved oxygen at room temperature (25°C). The remaining elements such as Si and Mg were kept at balanced levels in an attempt to minimize variations in graphite size and distribution among different samples. The corrosion resistance was evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization. Microstructure analysis of the cast alloys confirmed similarity in the graphite morphology among the different cast samples and the expected variations in the metallic matrix. In the absence of passivation, it was found that the addition of copper led to an increase in corrosion resistance, which could be attested by higher values polarization resistance and corrosion potential.