Wyniki wyszukiwania - BazTech

1

Badanie wpływu parametrów azotowania gazowego żeliwa sferoidalnego metodą ZeroFlow na kinetykę wzrostu warstw azotkowy

Tylkowska Marika, Paczkowska Marta, Ćwian Paulina, Małdziński Leszek

Przemysł Chemiczny

|

2026

|

T. 105, nr 6

592--596

PL

Próbki żeliwa sferoidalnego poddano kontrolowanemu azotowaniu gazowemu metodą ZeroFlow w temp. 550°C. Azotowanie przeprowadzono w piecu półprzemysłowym z pionową retortą, w atmosferze jednoskładnikowej NH ₃w ośmiu wariantach, zmieniając czas (2, 4, 10 i 24 h) oraz potencjał azotowy Nₚ (1,0 i 3,6). Badania miały na celu ocenę wpływu tych parametrów na kinetykę wzrostu oraz twardość i budowę fazową warstwy dyfuzyjnej. Po 24 h procesu grubość strefy związków azotków żelaza wzrosła do 12 μm (dla Nₚ = 1,0) oraz 18 μm (dla Nₚ = 3,6). Maksymalna twardość warstwy dla obu wartości potencjału wyniosła 500 HV0,05. Stwierdzono, że metoda ZeroFlow umożliwia precyzyjne kształtowanie grubości i twardości strefy modyfikowanej żeliwa sferoidalnego poprzez dobór parametrów atmosfery.

EN

Ductile Fe samples were subjected to controlled gas nitriding using the ZeroFlow method at 550°C, which was carried out in a semi-industrial furnace with a vertical retort, in a single-component NH₃ atmosphere, in 8 variants, varying the time (2, 4, 10, and 24 h) and the N₂ potential Nₚ (1.0 and 3.6). The effect of these parameters on the growth kinetics, hardness, and phase structure of the diffusion layer was assessed. After 24 h of the process, the thickness of the Fe nitride compd. zone increased to 12 μm (for Nₚ = 1.0) and 18 μm (for Nₚ = 3.6). The max. hardness of the layer for both potential values was 500 HV0.05. It was found that the ZeroFlow method allows for precise shaping of the thickness and hardness of the modified zone of ductile Fe by selecting the atmosphere parameters. The effect of these parameters on the growth kinetics, hardness and phase structure of the diffusion layer was assessed.

2

Opracowanie innowacyjnej technologii wytwarzania masywnych kadzi żużlowych o podwyższonych parametrach eksploatacji (SLAG LADLE TECH)

Paul Władysław, Piotrowski Krzysztof, Bednarczyk Paweł

Przegląd Odlewnictwa

|

2025

|

Vol. 75, nr 5-6

174--179

PL

W niniejszym artykule przedstawiona zostanie innowacyjna technologia wytwarzania masywnych kadzi żużlowych o podwyższonych parametrach eksploatacji. W żeliwie sferoidalnym przeznaczonym na masywne odlewy wielkogabarytowe o wadze powyżej 10 Mg, cnarakteryzujące się grubością ścian sięgającą 400 mm, w wyniku wydłużonego procesu krzepnięcia i stygnięcia metalu obserwuje się znaczne obniżenie własności mechanicznych. Proces technologiczny wytwarzania masywnych odlewów kadzi żużlowych cechuje się koniecznością doboru specjalnych parametrów. Jednym z takich parametrówjest temperatura zalewania odlewów, córa definiuje temperaturę uszlachetniania ciekłego metalu, zabieg sferoidyzacji i modyfikacji. Przedstawione badania obrazują efekt doboru parametrów procesu produkcyjnego na uzyskane własności mechaniczne żeliwa. Wpływ parametrów procesu na podwyższenie właściwości użytkowych odlewów, a także ograniczenie występowania wad powierzchniowych oraz porowatości w produkowanych odlewach. Poprawę własności mechanicznych żeliwa sferoidalnego uzyskano w wyniku opracowania odpowiedniego składu chemicznego żeliwa oraz zastosowania technologii uszlachetniania żeliwa wyjściowego metodą „Przewodu Elastycznego". Do procesu uszlachetniania ciekłego żeliwa metodą Przewodu elastycznego użyto nowatorskiego modyfikatora zapewniającego odpowiednią modyfikację żeliwa w obniżonej temperaturze procesu, mieszczącej się w zakresie 1330- 1370°C. Zastosowana technologia pozwoliła uzyskać podwyższone parametry eksploatacyjne masywnych kadzi żużlowych dla żeliwa sferoidalnego wynoszące: Rm min. 400 MPa, A5 min 10% (w wielkogabarytowych odlewach masywnych), porowatość max. 3%.

EN

This paper will present an innovative technolo¬gy for the manufacture of massive slag ladles with enhanced operating parameters. In ductile iron intended for massive large-volume castings weighing more than lOMg, characterised by wali thickness of up to 400mm, a significant reduction in mechanical properties is observed as a result of the prolonged solidification and cooling process of the metal. The technological process of manufacturing massive slag ladle castings is characterised by the need to select special parameters. One such parameter is the casting pour temperaturę, which defines the liquid metal refinement temperaturę, spheroidisation and modification procedurę. The research presented here illustrates the effect of the choice of production process parameters on the resulting mechanical properties of cast iron. Influence of process parameters on the enhancement of casting properties and the reduction of surface defects and porosity in produced castings. The improvement in the mechanical properties of ductile cast iron was achieved by developing an appropriate Chemical composition for the cast iron and applying the 'Flexible Duet' method in the cast iron refining technology. An innovative modifier was used for refining liquid cast iron using the Flexible Duet method, ensuring appropriate modification of the cast iron at a reduced process temperaturę within the rangę of 1330-1370°C. The technology used made it possible to obtain inereased performance parameters of massive slag ladles for ductile iron of: Rm min. 400 MPa, A5 min 10% - (in large-size massive castings), porosity max. 3%.

3

Thermodynamic Analysis and Impact of Quenching on Microstructure & Mechanical Properties of High Silicon Ductile Iron

David Joseph B., Pustal B., Weirich T., Bührig-Polaczek A.

Archives of Foundry Engineering

|

2025

|

Vol. 25, iss. 1

43--51

EN

Solid-solution-strengthened ferritic ductile iron (SSFDI) exhibits superior tensile strength to elongation ratios up to a critical silicon content of 4.3 wt.%. Beyond this threshold, this material experiences a sudden drop in ultimate tensile strength and elongation at breakage. Previous studies indicate that this is may be because of the formation of superstructures like B2 and D03 especially at regions with high silicon content. This study aims to comprehend thermodynamics behind phase transition during solid-state transformation in high silicon ductile iron. Using thermodynamic simulations, this current investigation tries to pinpoint the transition temperature from the ferritic phase to superstructure formation especially B2 superstructure. Additionally, analysis is made to see consequences of quenching above this transition temperature on microstructure, and mechanical properties. The results contribute insights into phase transitions in high silicon ductile iron, offering practical guidance for optimizing heat treatment processes. By isolating the transition temperature and evaluating the impact of quenching, we provide actionable strategies for controlling microstructural evolution and enhancing mechanical performance in SSFDI. In conclusion, this research represents a crucial advancement in realizing the full potential of high silicon ductile iron for engineering applications. The findings deepen our understanding of the material's behavior and furnish practical approaches for improving its mechanical properties through controlled heat treatments and quenching processes.

4

Structure Characteristics of Si/Si-Mo Ductile Irons Solidified on a Metallic Chill

Stan I., Anca D. E., Chisamera M., Riposan Iulian, Stan S.

Archives of Foundry Engineering

|

2025

|

Vol. 25, iss. 2

61--68

EN

The present work focuses on the structure characteristics of three un-inoculated ductile cast irons (0.035-0.045%Mgres), at high content of Si and Mo (I. 4.55%Si/4.71%CE; II. 5.25%Si/5.05%CE; III. 4.80%Si-2.30%Mo/4.75%CE) solidified on a cast iron chill, in furan resin sand moulds. At 4.55%Si iron, there resulted a chilled zone at 6-8mm, with carbides presence, lower graphite amount, higher nodule count and ferrite amount. Si increasing up to 5.25%Si led to a limited affected surface zone (up to 3mm), characterised by no carbides and the highest nodule count. Mo addition led to the most extensive chilled zone (11-15mm), with the lowest amount of graphite and ferrite, and the highest carbides amount, at the lowest nodule count. All irons are characterised by Type V, slightly irregular spheroidal graphite morphology, typical for the Roundness Shape Factor RSF=0.62-0.75 range, at the highest position for I, intermediary for II and at the lowest position for III cast irons. A higher Graphite Nodularity (NG) level resulted when it was calculated according to ISO 16112:2017 [CGI], comparing to ISO 945-4-2019 [DI]. By the use of the Sphericity Shape Factor (with graphite real perimeter), an intermediary position of NG was obtained; it is recommended to avoid the castings rejection, due to the lower values of NG resulted from ISO 945-4-2019 stipulation for High-Si DI. The increase of Si negatively affected the nodularity, while the supplementary Mo alloying led to the lowest NG. The chill solidification appears to have less effect on the NG of 4.55%Si iron, with the maximum influence for 4.8%Si-2.3%Mo iron and by the imposed RSF=min.0.80, especially for 5.25%Si content.

5

3D Phase-field Simulations of Spheroidal Cast Irons and Evaluation of Homogenized Elastic Mechanical Properties

Nellissery Rajan R., Eiken Janin

Archives of Foundry Engineering

|

2025

|

Vol. 25, iss. 1

91--102

EN

The Volumetric Multicomponent Multiphase Field model implemented in MICRESS® enables microstructure simulation of spheroidal graphite cast iron in 3D space. In this work, it is combined with the homogenization tool HOMAT to study the correlation between graphite characteristics and effective elastic mechanical properties. In a first step, the microstructure evolution of near-eutectic Fe-C-Si-(Mg) grades is simulated from the pure melt to the as-cast structure. The required thermodynamic and diffusion data are evaluated by run-time coupling to CALPHAD data. Temperature evolution is simulated by balancing latent heat release and heat extraction, considering the casting modulus and the mould diffusivity. During the initial solidification, dendritic austenite and spheroidal graphite nucleate and grow independently in the melt. After encapsulation by austenite, the graphite nodules continue to grow by interstitial diffusion of carbon. The eutectoid decomposition of primary austenite to ferrite and graphite is modelled under assumption of para-equilibrium conditions. The final as-cast structure is characterized by graphite nodules of varying size and morphology distributed in a polycrystalline, fully ferritic matrix. To generate representative volume elements (RVE) with different characteristics of graphite precipitates, a series of simulations are performed under independent variation of chemical composition, casting modulus and nucleation conditions. From each RVE, the graphite fraction, the nodule number, the mean nodule size and the mean sphericity are evaluated. In a second step, the RVEs are transferred to the HOMAT software and homogenized values for the Young's modulus, the shear modulus, and the Poisson's ratio are evaluated and discussed in correlation with the characteristic graphite properties and classic mean field approaches.

6

Comparison of the Mechanical Properties of Ductile Cast Iron Intended for Gas Gate Valves with Nickel Cast Iron with an Austenitic Matrix

Rączka Arkadiusz, Szczęsny A., Kopyciński D.

Archives of Foundry Engineering

|

2024

|

Vol. 24, iss. 3

36--42

EN

The study presents a comparison of the results of structural tests, impact strength and strength properties of cast iron EN-GJS-400-15, which is produced in industrial conditions and the ductile cast iron, with addition of nickel, in austenitic matrix. Due to the ongoing energy transformation and attempts to inject hydrogen into existing gas grids, gas fittings manufacturers are looking for materials that will be more resistant to the destructive effects of hydrogen than the currently used ductile cast iron. The aim of the work was to obtain cast iron with the addition of nickel (about 20%) with similar strength parameters, better impact strength, both at room temperature and at lower temperatures, as well as a stable austenitic matrix in ductile cast iron. All assumptions were achieved. In the future, research should be undertaken to develop an economically optimal chemical composition, without a significant loss of strength properties, and the resistance of gate valves made of austenitic cast iron to the destructive effects of hydrogen should be examined. The work is preliminary research.

7

Casting Production in Poland Versus European Trends in 21st Century

Soiński M.S., Jakubus A.

Archives of Foundry Engineering

|

2024

|

Vol. 24, iss. 3

57--62

EN

This article presents changes of the total casting production volumes and of the production of castings made from basic casting alloys in Poland, in Europe and worldwide in years 2001–2021. Analogous casting production parameters were compared for Poland, Europe and countries being the leading European and global manufacturers in years 2001, 2011 and 2021. The leading casting manufacturers in Europe (with the manufacturing volume exceeding 1 million tons in the mentioned years) include Germany, Italy, the Ukraine, France and Spain. For years, the largest casting manufacturer worldwide has been China. In 2001–2021, global casting production increased from ca. 68 million tons to ca. 97 million tons (i.e. by ca. 42%), whereas the European one decreased from ca. 17 million tons to ca. 12 million tons (i.e. by close to 30%). In the analyzed period, the Polish production volume grew from ca. 0.75 million tons to ca. 0.88 million tons (i.e. by ca. 17%). The presented data reveal the decreasing importance of gray cast iron and cast steel and the increasing one of ductile cast iron and aluminum alloys. However, the Polish average annual growth rate for aluminum alloy casting production was 10.3%, whereas the global one was 3% and the European one 0.7%.

8

Modelling of phase transformations occurring in the process of austempered ductile iron manufacturing

Olejarczyk-Wożeńska Izabela, Mrzygłód Barbara, Adrian Henryk

Archives of Civil and Mechanical Engineering

|

2024

|

Vol. 24, no. 3

art. no. e195, 2024

EN

The paper presents mathematical models and their implementation in C # language describing the phase transformations occurring in the process of austempered ductile iron (ADI) manufacture. The research includes two main stages: austenitization and isothermal holding at the bainitic range. The influence of free energy of austenite and ferrite on transformations was taken into account. Parameters of models were identified based on inverse analysis and experimental research. As part of the research, verification and validation of the developed models was carried out based on the results of experimental research. The tool developed and implemented enables the analysis of phase transformations occurring during heat treatment with isothermal holding of ductile iron with Ni addition.

9

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

|

2023

|

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.

10

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

|

2023

|

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.

11

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

|

2023

|

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.

12

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

Stawarz Marcin, Lenert Małgorzata, Piasecki Karol

Archives of Foundry Engineering

|

2023

|

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.

13

Kierunek minimalizacji powstania odpadów podczas budowy sieci wodociągowej i kanalizacyjnej

Nerkowski Mateusz

Gaz, Woda i Technika Sanitarna

|

2022

|

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.

14

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

|

2022

|

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.

15

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

|

2022

|

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.

16

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

|

2022

|

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.

17

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

|

2021

|

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.

18

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

|

2021

|

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.

19

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

|

2021

|

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.

20

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

Dwulat Rafał, Janerka K., Grzesiak K.

Archives of Foundry Engineering

|

2021

|

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.