Wyniki wyszukiwania - Biblioteka Nauki

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Methodology of integrated modeling of high-temperature steel processing in the aspect of supporting the design of new technologies

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Hojny M. , Głowacki M.

Journal of Theoretical and Applied Mechanics

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2020

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tom Vol. 58 nr 2

361--371

EN

The article presents main assumptions of the methodology of integrated modeling of hightemperature steel processing in the aspect of supporting the design of new technologies. The developed solution uses a methodological research capability of modern Gleeble thermomechanical simulators to simulate physical processes, and the benefits of numerical modeling. This allows for restricting the number of expensive experimental tests to the minimum, e.g. by selecting a suitable heating schedule to achieve the desired temperature at the sample section, or getting additional information about the process, eg. estimating the zones with diversified grain growth dynamics, information on local cooling rates at any point within the volume of the sample tested. Mathematical models are original solutions of the developed methodology, such as the thermomechanical model of steel deformation in the semi-solid state, and the multi-scale model of resistance heating coupled with grain growth modelling in the micro scale. The work is supplemented with the main assumptions of the developed mathematical models together with examples of their practical use to support physical simulations.

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Cellular Automata model of carbonitrides precipitation process in steels

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Marynowski P. , Adrian H. , Głowacki M.

Computer Methods in Materials Science

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2018

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tom Vol. 18, No. 4

122--129

EN

Cellular Automata (CA) model of carbonitride precipitation in microalloyed steels is presented in the paper. The model accounts for an increase of dislocation density due to plastic deformation and predicts kinetics of precipitation as well as stereological parameters of precipitates. Precipitation of compounds plays crucial role in controlling of properties of alloys. In low alloyed steels the microalloying elements: Ti, Nb, V are added in order to control their microstructure and mechanical properties. The most important tool in development of new processing technologies is numerical modelling. Modelling is a mathematical description of the relation between the main process variables and the resulting material properties. Many thermodynamics models were developed in the second half of the 20th century. For example the model of carbonitrides precipitation in microalloyed steels is considered works of Dutta & Sellars (1987), Dutta et al. (1991), Dutta et al. (2001). The models allow calculate kinetics of precipitation and stereological parameters of precipitates as a function of processing parameters. CA model proves to be very efficient in modelling various phenomena in materials science. The transition rules transfer the mathematical model and the knowledge regarding precipitation into the cellular automata space.

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Computer modelling of the ablation casting process and prediction of the strength properties of AC-42000 castings

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Małysza M. , Puzio S. , Major-Gabryś K. , Głowacki M. , Wilk-Kołodziejczyk D. , Kamińska J.

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2022

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tom Vol. 22, No. 2

79--88

EN

The demand for castings with superior properties has compelled the development and optimization of manufacturing technologies. By further developing already known techniques, we are able to contribute to the introduction of new research possibilities. The article presents the methodology of conducting simulation tests of the gravity casting process into sand moulds with the use of ablation. The ablation technique consists in spraying water through evenly spaced nozzles onto a mould into which the liquid casting alloy has been poured. The conducted research focuses on an alloy from the group of Al-Si alloys. In order to compare the effects of different techniques, additional tests were carried out for gravity casting into sand and metal die moulds. At the same time, virtual experiments were conducted to develop a simulation methodology for ablation casting technology, taking into account mould degradation. Additionally, the possibility of predicting the final mechanical properties of various manufacturing technologies was tested. Destructive tests were carried out to determine the mechanical properties in the cast samples, as well as microstructure tests and secondary dendrite spacing. The results of the mechanical tests are compared with the predicted simulation properties.