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1

Research on New Al-Ag-Mo Alloys Dedicated to Wire Applications in Overhead Power Lines

Grzebinoga Justyna, Mamala Andrzej, Ściężor Wojciech, Kowal Radosław

Journal of Casting & Materials Engineering

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2023

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Vol. 7, no. 1

9--14

EN

The latest research work in the field of electric power systems focuses on the development of new wire materials which will allow the increase of the transmission capacity of power lines currently in use. The reason for this research was the often limited possibilities of continuous and failure-free transmission of electricity. In this paper, the authors present research on a new aluminium-based alloy dedicated for use as a conductive braid in the HTLS cable group. There are many technical solutions for this group of cables on the market, although they are solutions with a number of disadvantages, ranging from their high price, various operational shortcomings, complicated installation techniques, and ending with the risk of monopolistic practices, which is related to the inability to attract several competitive suppliers. The main aim of the research was to develop a new alloy based on aluminium with the addition of silver and molybdenum dedicated for use in special overhead power cables. Experimental research on new materials focused on obtaining the necessary knowledge to produce an overhead wire from these alloys with higher current carrying capacity in relation to the currently used conventional wire materials based on aluminium.

2

Numerical Modelling for the Effect of Metal-mould Air Gaps on Shell Thickness in Horizontal Continuous Casting of Cast Iron

Chawla Ashish, Tiedje N. S., Spangenbe Jon

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 1

53--60

EN

This paper presents a numerical model for the horizontal continuous casting of cast iron (HCCCI). A computational three-dimensional (3D) steady-state, coupled with fluid flow and heat transfer simulation model was developed and validated against experimental results to study the shell thickness and solidification of ductile cast iron. The study introduces the influence of an air gap at the melt-mould interface, which has long been known to have a detrimental effect on the efficiency of the process. The effect of the length and thickness of the melt-mould air gaps (also referred to as top air gaps) on solidification and remelting of the solid strand is studied. Parametric studies on top air gaps suggested a substantial effect on the solid and eutectic area at the top-outlet end of the die when the length of air gas was varied. This study serves to create a foundational and working model with the overall objective of process optimisation and analyzing the effect of operating process input parameters on the shell thickness of the strand.

3

New Ecological Cast Bronzes for Fittings Manufactured from Recycled Waste

Malec Witold, Cwolek Beata, Brudny Anna, Juszczyk Barbara, Kulasa Joanna, Hury Anna, Marek W., Stolorz K., Wróbel D., Filipowicz A.

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 1

37--42

EN

The article presents tests on a new lead-free bronze CuSn4Zn2PS, intended for fittings for contact with drinking water, in which the addition of lead was replaced with sulphur. The subject of the experimental work was the production of semi-finished products from this alloy based on the charge coming entirely from waste generated after machining. A specialized pilot line was used for the tests, and after cleaning, the waste was melted and then were continuously cast in the form of rods and hollow rods. The cleaning efficiency was assessed, and the manufactured semi-finished products were subjected to tests, including the assessment of the chemical and mechanical homogeneity and the structure of the test batch of the semi-finished casting products in terms of the possibility of manufacturing products meeting the requirements of technical specifications. The obtained results, both in terms of a stable chemical composition, homogeneous and reproducible mechanical properties, fully compliant with the specifications for fittings bronzes (CC499K), as well as the lack of faults of the obtained semi-finished products, despite a very large share of waste material, indicate the possibility of using the tested recycling method for the production of semi-products of sulphur bronze, which is an alloy that is relatively difficult to manufacture.

4

Development of Process Conditions for the Preparation of Copper Alloys Post-Production Chips for the Continuous Casting Process

Malec Witold, Cwolek Beata, Brudny Anna, Kulasa Joanna, Marek W., Stolorz K., Wróbel D., Filipowicz A.

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 2

43--50

EN

The paper presents the results of research aimed at developing assumptions for the preparation of a charge in the form of fine scrap copper alloys (chips/shells) guaranteeing effective removal of impurities and obtaining a metal bath of the required metallurgical quality. The tests were conducted for tin-zinc-lead bronze of the CC499K grade. As part of the work, the characteristics of this type of waste available on the market were made in terms of quality and the possibility of their use for the production of both alloys and finished products, taking into account the elimination of harmful impurities that may ultimately affect the production process adversely. The subject of the work was the selection of appropriate waste cleaning methods in the form of an oily shell in the CC499K (CuZn5Sn5Pb2) grade and its drying in terms of increasing the use of impure waste from machining as scrap for direct melting. The waste was assessed in relation to individual parameters. The research was carried out on 3 groups of waste, with varying degrees of moisture.

5

Optimisation of the Thermal Process in Ladle Metallurgy in Terms of the Impact on Energy Consumption and the Environmental Burden During Steel Production

Lampa Martin, Mokrošová Lenka

Rocznik Ochrona Środowiska

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2022

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Tom 24

246--259

EN

The paper focuses on reducing the energy intensity of ladle metallurgy as part of steel production and the associated reduction of pollutant emissions. It can be achieved by optimising the thermal work of metallurgical aggregates in terms of the impact on energy consumption and the environmental burden of steel production. It is about minimising the heat loss of liquid steel in the casting ladle throughout the entire process, from the melting equipment, through the extra-furnace processing, to the continuous casting of the steel.

6

The Adjustment of the Tundish Water Model of Continuous Casting

Blaško Peter, Bulko Branislav, Petrík Jozef, Demeter Peter, Socha Vladimir, Hanáková Lenka, Palfy Pavol, Solc Marek, Vasilňáková Andrea

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 1

97--104

EN

Whereas approximately 96.3% of the steel produced worldwide is made by continuous casting, great emphasis is put on the superior efficiency of this process. The water model of the tundish and mathematical modeling is often used for the simulation of the steel flow during continuous casting. The experiments were performed on a model of the tundish with two outlets, at two casting speeds (0.8 m.s-1 and 1.2 m.s-1). Eight setups of the tundish were evaluated, which differed in the design of the dams (with or without drainage holes), in their distance from the center of the tundish, and their height. The contribution of the work is the analysis of phenomena in the tundish water model in conditions of repeatability (ten repetitions). The goal is to find the setup providing the most symmetrical flow, with the minimum difference in the residence times Δτ on the two outlets. Taking into account the results obtained at both casting speeds, the most preferred is setup 2 with the 87 mm high dams placed 587 mm from the center of tundish (Δτ = 0.5). The setup 3 (Δτ = 8.25) appears to be the least appropriate. The higher the casting speed, the higher the number of unsuitable arrangements.

7

Numerical Analysis of the Influence of the Modification of the Ladle Shroud on Fluid Flow Behavior in a One-strand Tundish during Continuous Steel Casting

Suchan Hanna, Cwudziński Adam

Journal of Casting & Materials Engineering

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2021

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Vol. 5, no. 4

75--83

EN

A tundish is a device from which liquid steel is pour into a mold. Therefore tundish hydrodynamic conditions have a significant impact on solidification during continuous steel casting (CSC) process. Modification of ladle shroud workspace, allows for the modification of liquid steel movement in the tundish. In the following work, numerical simulations were performed which allowed the impact of the modification of the ladle shroud workspace on the liquid steel flow structure in a one-strand tundish to be determined. In order to assess the impact of the modification of the ladle shroud on the behavior of the liquid steel in the tundish, simulations were performed, on the basis of which the percentage share of stagnant, ideal mixing and plug flow zones were determined. In addition, the mixing parameters were determined, allowing the estimation of casting duration during sequential casting. The flow fields of liquid steel for each modification of the ladle shroud were performed. The average velocity of liquid steel flowing through the tundish, the Reynolds number and turbulent intensity were also described. The obtained results showed, among others, that the application of three cylinders with a diameter of 0.041 m into the ladle shroud with a diameter of 0.11 m increases the share of active flow in the tundish in relation to the tundish with Conventional Ladle Shroud. At the same time, applying a ladle shroud with a diameter of 0.11 m during casting is the most favorable in relation to the hydrodynamics of the tundish.

8

Wpływ modyfikacji wylewu osłonowego na przepływ ciekłej stali w dwuwylewowej kadzi pośredniej

Suchan Hanna, Cwudziński Adam

Hutnik, Wiadomości Hutnicze

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2021

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Vol. 88, nr 3-4

2--9

PL

Kadź pośrednia jest jednym z urządzeń, przez które przepływa ciekła stal podczas procesu ciągłego odlewania i które pełni ważną rolę w kontroli zachowania się kąpieli metalowej. Przeprowadzone symulacje komputerowe miały na celu analizę wpływu modyfikacji wylewu osłonowego na hydrodynamikę ciekłej stali przepływającej przez dwuwylewową kadź pośrednią. Głównym parametrem, na który zwrócono uwagę w badaniach była prędkość przepływu ciekłej stali kształtująca się w przestrzeni roboczej wylewu osłonowego oraz w objętości kadzi pośredniej. Określono również wpływ turbulencji na procentowy objętościowy udział poszczególnych przepływów oraz na stopień mieszania kąpieli metalowej.

EN

Tundish is the one of the equipment of the continuous casting process, during the liquid steel flows through it, and it plays an important role of control metal bath behavior. Aim of the conducted computer simulations was to analyze influence of the modification of the ladle shroud on liquid steel hydrodynamics flowing through the two-strand tundish. The main parameter noted in the article was velocities in the working space of ladle shroud and in the volume of the tundish. The influence of the turbulence on the percentage volume of the individual flows and the mixing degree of the metal bath was also determined.

9

Mathematical modelling of the continuous casting of blooms and beam blanks

Gomes Daniela Fátima, Braga Bernardo Martins, Tavares Roberto Parreiras, Bagatini Maurício Covcevich

Computer Methods in Materials Science

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2021

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Vol. 21, No. 3

149--156

EN

Defects and discontinuities generated in continuous casting are directly related to heat transfer during the process and the stresses to which the material is subjected. Knowledge of these phenomena is essential for both process safety and the quality of the final product. The aim of this work is to analyze the thermo-mechanical behavior of blooms and beam blanks during continuous casting. The continuous casting machine considered in this study is used to cast both blooms and beam blanks. The secondary cooling can be divided into cooling zone z0, cooling zone z1, cooling zone z2, and cooling zone z3. For each geometry, there are specific molds, z0, z1, z2 (sprays and support rollers), which need to be replaced when there is a geometry shift. The changing of the cooling segments brings security risks for the operators and reduces the continuous casting availability. Therefore, it is desired to have a common z2 for both blooms and beam blanks to reduce operational risk exposure and increase the machine production rate. For this to be possible, it is necessary to assess the temperature and resistance of the solidified skin, the effects of thermal stresses, ferrostatic pressure, and contact stresses. This work is the first step in this study. A thermo-mechanical model was developed for both geometries. The thermal model was verified by temperature measurement and shell measurements of blackouts. Finally, the results were analyzed and compared.

10

Dynamiczne wyznaczanie przegrzania stali za pomocą kontrolnego pomiaru temperatury likwidusu oraz ciągłego pomiaru temperatury stali w kadzi pośredniej maszyny COS

Węgrzyn Wojciech, Pieprzyca Jacek

Hutnik, Wiadomości Hutnicze

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2020

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Vol. 87, nr 6

160--167

PL

W artykule omówiono zastosowaną w praktyce metodologię dynamicznego wyznaczania przegrzania stali oraz jej wpływ na zwiększenie precyzji sterowania procesem ciągłego odlewania stali na maszynie COS. Przeprowadzono również analizę porównawczą metody alternatywnej kontrolnego pomiaru temperatury stali w kadzi pośredniej z wykorzystaniem przykładowych opomiarowanych sekwencji. Wskazano na potencjalne zagrożenia wynikające z bazowania podczas sekwencji ciągłego odlewania na pomiarze kontrolnym w porównaniu do pomiaru ciągłego oraz różnice występujące pomiędzy temperaturą likwidusu liczoną wg różnych modeli matematycznych i mierzoną czujnikiem zanurzeniowym.

EN

This article briefly reviews dynamic superheat of steel determination in practice and presents the outcomes for more accurate continuous casting process control. The competitive methods have been evaluated using casting sequences with both continuous and dip steel temperature measurement. The potential threats of operating a caster based on dip temperature only in comparison with continuous measurement have been indicated along with the differences in liquidus temperatures determined by various mathematical models and the physically measured value.

11

Thermal simulation of a continuous casting process subjected to water-sprays cooling

Mzad Hocine, Otmani Abdessalam

Archives of Thermodynamics

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2020

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Vol. 41, no 2

185--199

EN

As in many thermal processing technologies, there is a delicate balance between productivity and quality during ingot cooling process. Higher cooling velocities increase productivity but also create higher temperature gradients inside the ingot. Such a fast cooling does not leave sufficient time to establish the equilibrium within the solid, thus the final metal structure is strongly affected by the set up cooling mode throughout the liquid metal solidification. The first intention in this paper is to compare between three cooling modes in order to identify the required mode for a continuous casting process. Then, we study the influence of heat transfer coefficient on metal liquid-to-solid transition through the spray-cooled zone temperature and the metal latent heat of solidification. A gray iron continuous casting process subjected to water-sprays cooling was simulated using the commercial software for modeling and simulating multiphysics and engineering problems. The primary conclusions, from the obtained results, show the forcefulness of water spray cooling regarding standard cooling. Afterward, we highlight the great influence of heat transfer coefficient on the location of transition region as well as the relationship between heat transfer coefficient, wall outer temperature, latent heat dissipation, and the solidification time.

12

Preparation and Microstructure Evolution of Continuous Unidirectional Solidification Tin Bronze Alloy at Different Continuous Casting Speed

Luo Jihui

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 2

118--122

EN

The mold temperature of the downward continuous unidirectional solidification (CUS) cannot be controlled higher than the liquidus of alloys to be cast. Therefore, the continuous casting speed becomes the main parameter for controlling the growth of columnar crystal structure of the alloy. In this paper, the tin bronze alloy was prepared by the downward CUS process. The microstructure evolution of the CUS tin bronze alloy at different continuous casting speeds was analysed. In order to further explain the columnar crystal evolution, a relation between the growth rate of columnar crystal and the continuous casting speed during the CUS process was built. The results show that the CUS tin bronze alloy mainly consists of columnar crystals and equiaxed crystals when the casting speed is low. As the continuous casting speed increases, the equiaxed crystals begin to disappear. The diameter of the columnar crystal increases with the continuous casting speed increasing and the number of columnar crystal decreases. The growth rate of columnar crystal increases with increasing of the continuous casting speed during CUS tin bronze alloy process.

13

Consecutive Casting of Iron Bimetal with Low-Carbon Steel Interface Plate

Purwadi W., Bandanadjaja B., Idamayanti D., Lilansa N.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 1

95--104

EN

Consecutive casting of bimetallic applies consecutive sequences of pouring of two materials into a sand mold. The outer ring is made of NiHard1, whereas the inner ring is made of nodular cast iron. To enable a consecutive sequence of pouring, an interface plate made of low carbon steel was inserted into the mold and separated the two cavities. After pouring the inner material at the predetermined temperature and the interface had reached the desired temperature, the NiHard1 liquid was then poured immediately into the mold. This study determines the pouring temperature of nodular cast iron and the temperature of the interface plate at which the pouring of white cast iron into the mold should be done. Flushing the interface plate for 2 seconds by flowing nodular cast iron liquid as inner material generated a diffusion bonding between the inner ring and interface plate at pouring temperatures of 1350°C, 1380°C, and 1410°C. The interface was heated up to a maximum temperature of 1242°C, 1260°C, and 1280°C respectively. The subsequent pouring of white cast iron into the mold to form the outer ring at the interface temperature of 1000°C did not produce a sufficient diffusion bonding. Pouring the outer ring at the temperature of 1430°C and at the interface plate temperature of 1125°C produced a sufficient diffusion bonding. The presence of Fe3O2 oxide on the outer surface of the interface material immediately after the interface was heated above 900⁰C has been identified. Good metallurgical bonding was achieved by pouring the inner ring at the temperature of 1380°C, interface temperature of 1125°C and then followed by pouring of the outer ring at 1430⁰C and flushing time of 7 seconds.

14

Badania nad procesem odlewania ciągłego oraz własności stopów aluminium w gat. EN AW-2007

Ściężor Wojciech, Kowal Radosław, Mamala Andrzej, Kwaśniewski Paweł

Rudy i Metale Nieżelazne Recykling

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2019

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R. 64, nr 3

15--18

PL

Z uwagi na wysokie własności użytkowe, a przede wszystkim wysoką podatność na obróbkę skrawaniem, elementy wykonane ze stopu aluminium serii 2XXX znajdują szerokie zastosowanie w wielu gałęziach współczesnego przemysłu. Tradycyjna technologia ich wytwarzania bazuje na procesie odlewania wielkogabarytowych wlewków oraz następującego po nim procesie wyciskania. W artykule zaprezentowano wyniki badań nad alternatywną metodą ich wytwarzania, a więc procesem ciągłego odlewania profili okrągłych o średnicy 40 mm. W dalszej części przedstawiono analizę ich własności mechanicznych, elektrycznych oraz składu chemicznego przeprowadzonych dla odlewów w gat. EN AW-2007.

EN

Elements manufactured from aluminum alloys series 2XXX are widely used in many branches of modern industry due to their high functional properties and high susceptibility to machining. Traditionally the production of such elements is based on the casting process of large-sized ingots and their subsequent extrusion process. This article presents the research results of the alternative method of their manufacturing which is the process of continuous casting of round profiles with a diameter of 40mm. The article includes the analysis of mechanical, electrical and chemical properties of the EN AW-2007 alloy castings.

15

Hydrodynamic conditions of flow in the tundish depending on selected technological parameters for different steel groups

Warzecha M., Merder T., Warzecha P., Hutny A. M.

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 1

65--70

EN

The presented results of investigations are part of a larger study focused on the optimization of the flow and mixing of liquid steel in the industrial tundish of continuous casting machine. The numerical simulations were carried out concern the analysis of hydrodynamic conditions of liquid steel flow in a tundish operating in one of the national steelworks. Numerical simulations were performed using the commercial code ANSYS Fluent. The research concerns two different speeds of steel casting. In real conditions, these speeds are the most commonly used in the technological process when casting two different groups of steel. As a result of computational fluid dynamics (CFD) calculations, predicted spatial distributions of velocity and liquid steel turbulence fields and residence time distribution (RTD) curves were obtained. The volume fractions of different flows occurring in the tundish were also calculated. The results of the research allowed a detailed analysis of the influence of casting speed on the formation of hydrodynamic conditions prevailing in the reactor.

16

Peritectic Determination by a Melt Deck Thermal Analysis System

Tuttle R. B.

Archives of Foundry Engineering

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2019

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iss. 1

83--88

EN

There has been a growing interest in the peritectic due to increasing productivity, quality, and alloy development. Differential scanning calorimetry (DSC) has traditionally been used to study steel solidification but suffers significant limitations when measuring the solidus and peritectic. This work covers a new thermal analysis system that can characterize the peritectic reaction. Heats of AISI/SAE 1030 and 4130 steel were poured to provide some benchmarking of this new technique. The peritectic was detected and the reaction temperature measured. Measurements agree reasonably well with reference information. A review of the literature and thermodynamic calculations did find some disagreement on the exact temperatures for the peritectic and solidus. Some of this difference appears to be related to the experimental techniques employed. It was determined that the system developed accurately indicates these reaction temperatures. The system provides a unique method for examining steel solidification that can be employed on the melt deck.

17

Modeling of Heat Engineering Parameters of Casting and Rolling Complexes Work

Biryukov A., Ivanova A.

Archives of Foundry Engineering

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2019

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iss. 3

11--14

EN

The paper consists the problem of developing a scientific toolkit allowing to predict the thermal state of the ingot during its formation in all elements of the casting and rolling complex, between the crystallizer of the continuous casting machine and exit from the furnace. As the toolkit for the decision making task the predictive mathematical model of the ingot temperature field is proposed. Displacement between the various elements of the CRC is accounted for by changing the boundary conditions. Mass-average enthalpy is proposed as a characteristic of ingot cross-section temperature state. The next methods of solving a number of important problems with the use of medium mass enthalpy are developed: determination of the necessary heat capacity of ingots after the continuous casting machine for direct rolling without heating; determination of the rational time of alignment of the temperature field of ingots having sufficient heat capacity for rolling after casting; determination of the total amount of heat (heat capacity) required to supply the metal for heating ingots that have insufficient amount of internal heat.

18

Analysis of the Impact of Modifiers on the Formation of Non-metallic Inclusions During Continuous Casting of CuZn39Pb2 Brass

Bydałek A. W., Kula A., Błaż L., Najman K.

Archives of Foundry Engineering

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2019

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iss. 3

21--26

EN

In this paper results of microstructural observations for series of CuZn39Pb2 alloys produced from qualified scraps are presented. The individual alloy melts were differentiated in terms of thermal parameters of continuous casting as well as refining methods and modifications. Structural observations performed by SEM and TEM revealed formation of different types of intermetallic phases including “hard particles”. EDS results show that “hard particles” are enrich in silicon, phosphorus, iron, chromium and nickel elements. Additionally, formation of Al-Fe-Si and Al-Cr in alloy melts was observed as well. It was found that quantity and morphology of intermetallic phases strongly depends upon the chemical composition of raw materials, process parameters, modifiers and refining procedure applied during casting. It was observed that refining process results in very effective refinement of intermetallic phases, whereas modifiers, particularly carbon-based, results in formation of large particles in the microstructure.

19

MAGMA CC – autonomiczna inżynieria w odlewaniu ciągłym

Hutnik, Wiadomości Hutnicze

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2018

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Vol. 85, nr 2

63--64

PL

Odlewanie ciągłe jest dominującą technologią produkcji półwyrobów hutniczych. Zwiększenie wydajności przy zachowaniu odpowiedniej jakości i ekonomiczności procesu jest głównym celem optymalizacji procesów odlewania ciągłego we wszystkich jego odmianach. MAGMA CC, samodzielne oprogramowanie symulacyjne firmy MAGMA, umożliwia realizację tego celu poprzez wykorzystanie wirtualnych eksperymentów oraz automatycznej optymalizacji.

EN

Continuous casting is the preferred process for manufacturing semi-finished products. Increasing productivity without decreasing quality and efficiency is the main objective for all continuous casting processes. MAGMA CC, stand-alone simulation software from MAGMA, enables fulfilling this objective using Design of Experiments and autonomous optimization.

20

Analiza procesu ciągłego odlewania półwyrobów z brązu cynowo-cynkowo-ołowiowego przeznaczonych na obrabiane mechanicznie elementy armatury

Wierzbicki Ł., Cwolek B., Juszczyk B., Kulasa J., Malec W.

Hutnik, Wiadomości Hutnicze

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2018

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Vol. 85, nr 9

322--326

PL

W pracy przedstawiono analizę procesu ciągłego odlewania półwyrobów z brązu cynowo-cynkowo-ołowiowego przeznaczonego na obrabiane mechanicznie elementy armatury. Przedstawiono wyniki badań zmierzające do określenia przyczyn powstawania wad podczas procesu ciągłego odlewania. W tym celu wykonano analizę procesu ciągłego odlewania, rodzaju, postaci stosowanych materiałów wsadowych i pomocniczych oraz powstających wad. Na podstawie otrzymanych wyników badań, w celu udoskonalenia procesu, przedstawiono zakres wprowadzonych zmian i ich wpływ na jakość wytwarzanych wyrobów.

EN

The paper presents an analysis of the continuous casting process of semi-finished product made of tin-zinc-lead bronze, designed to mechanically machined elements of fittings. The results of tests to determine the causes of defects during the continuous casting process are presented. For this purpose, an analysis of the continuous casting process, as well as the type, the form of batch and auxiliary materials, and the appeared defects were made. Based on the results of the research, in order to improve the process, the scope of introduced changes and their impact on the quality of manufactured products are presented.