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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

The Impact of Composition and the Densification Level of Furan Molding Compounds on the Strength of Large-Size Casting Molds

Petrus Ł., Bulanowski A., Kołakowski J., Urbanowicz M., Sobieraj J., Jelonek M., Brzeżański M., Zych J. S., Janerka K.

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 4

1431--1436

EN

The paper presents the test results of molding compounds, sand casting molds and their analysis. The subject of testing was compound containing furan resins prepared according to the following recipe: matrix – regenerate 90% + fresh sand – 10%, furanresin – 1.10% by weight, hardener – 0.40% by weight. The impact of adhesive type and its quantity (Quan = 0.90, 1.1 and 1.5%) on the strength indexes of molding compound subject to densification was analyzed. The publication presents the test results: tensile strength Rm, compressive strength Rc and flexural strength Rg, as well as compound permeability as function of its density. The analysis also covers the impact of density level on mold strength and the distribution of density level along the mold height. Based on the test results, it was found that the best method to obtain high strength molds made from compounds with chemical adhesives was to densify it by vibrating the system: match plate – molding flask – compound filling the mold. The effectiveness of this densification method depends on the amplitude and frequency of vibrations.

3

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.

4

Impact of spatial planning on the pre-investment phase of the development process in the residential construction field

Sobieraj J.

Archives of Civil Engineering

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2017

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Vol. 63, nr 2

113--130

EN

Insufficient due planning policy in Poland is subject to widespread and justified criticism. This applies to all levels of spatial management. Legal instruments governing spatial planning in Poland are passive - setting out only the legal framework corresponding to a particular area. They regulate what might be developed within its boundaries, however, they do not specify how it is to be accomplished. Therefore, there is a need to develop an integrated spatial development planning, in which also investors and/or stakeholders would be involved. Apart from answering to the question of what is going to be developed, it will also provide a very comprehensive and flexible implementation strategy having regard to different timelines and local amenities (facilities). This paper also brings an example showing how the spatial planning strategy was conducted for the development of the "Fort Bema" housing estates in the Warsaw district of Bemowo. It highlights the relevance of the planning phase for the subsequent in-use (operating) phase.

PL

Brak racjonalnej polityki przestrzennej w Polsce jest przedmiotem powszechnej i uzasadnionej krytyki. Dotyczy to wszystkich poziomów zarządzania przestrzenią. Jak pokazują raporty środowisk naukowych, przedsiębiorców i organizacji zawodowych, poparte dodatkowo postulatami organizacji samorządowych i społecznych, nieracjonalny system zarządzania przestrzenią powoduje wymierne i rosnące straty społeczne oraz gospodarcze [7]. Jest to szczególnie widoczne z perspektywy praktyka zarządzania procesami inwestycyjnymi. W dokumencie zatytułowanym: „Tezy do naprawy prawodawstwa przestrzennego” przygotowanym przez Unię Metropolii Polskich czytamy: „Chaos przestrzenny ma negatywne skutki ekonomiczne i ekologiczne. (...) Powoduje nieracjonalny wzrost kosztów budowy i utrzymania infrastruktury technicznej i społecznej (...)” [7]. W rezolucji IV Kongresu Miast Polskich (2012) czytamy następujące postulaty: ”Prawo winno umożliwić prowadzenie racjonalnej polityki przestrzennej, wprowadzając równocześnie bariery ustawowe i procedury nadzorcze, które ograniczają działania szkodliwe społecznie i gospodarczo. (...) Zreformowane prawo winno ułatwiać inwestowanie, upraszczając procedury i eliminując bariery administracyjne (...)” [8]. W swoim referacie przybliżyłem system planowania przestrzennego obowiązujący w Polsce wraz z obowiązującymi aktami prawnymi oraz wyszczególniłem zadania władz samorządowych i krajowych w zakresie planowania przestrzennego w podziale na poziom decyzyjny: gminy, powiatu, województwa i kraju. Na każdym z poziomów decyzyjnych są do opracowania różne dokumenty: od miejscowych planów zagospodarowania, aż po koncepcje przestrzennego zagospodarowania kraju.