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1

Spatial Thermo-Mechanical Model of Mushy Steel Deformation Based on the Finite Element Method

Hojny M., Dębiński T., Głowacki M., Nguyen Trang Thi Thu

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 2

17--28

EN

The paper reports the results of work leading to the construction of a spatial thermo-mechanical model based on the finite element method allowing the computer simulation of physical phenomena accompanying the steel sample testing at temperatures that are characteristic for the soft-reduction process. The proposed numerical model is based upon a rigid-plastic solution for the prediction of stress and strain fields, and the Fourier-Kirchhoff equation for the prediction of temperature fields. The mushy zone that forms within the sample volume is characterized by a variable density during solidification with simultaneous deformation. In this case, the incompressibility condition applied in the classic rigid-plastic solution becomes inadequate. Therefore, in the presented solution, a modified operator equation in the optimized power functional was applied, which takes into account local density changes at the mechanical model level (the incompressibility condition was replaced with the condition of mass conservation). The study was supplemented with examples of numerical and experimental simulation results, indicating that the proposed model conditions, assumptions, and numerical models are correct.

2

Measurement of Magnetization Curve in a Steel Sample

Graca P.

Zeszyty Naukowe. Elektryka / Politechnika Opolska

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2013

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z. 69

27--28

EN

In the paper, a measurement method is presented which permits to investigate the magnetization curve in a steel sample.

3

Opracowanie metodyki przygotowywania próbek stalowych za pomocą urządzenia PECS do badań przy użyciu elektronowego mikroskopu skaningowego FEI

Wojtas J., Radwański K., Gazdowicz J.

Prace Instytutu Metalurgii Żelaza

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2008

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T. 60, nr 3

47-49

PL

Celem pracy było określenie możliwości wykorzystania i wdrożenia w warunkach Instytutu czyszczarko-napylarko-trawiarki PECS firmy Gatan - USA. Urządzenie PECS umożliwia usuwanie nalotów i rys oraz precyzyjne wytrawianie zarówno bardzo delikatne, potrzebne dla największych powiększeń, jak i bardzo głębokie - dla małych powiększeń, a także nanoszenie warstw węgla i metali o precyzyjnie określonej żądanej grubości. Wykonano trawienie i czyszczenie zgładów, nanoszenie i usuwanie warstw o żądanej grubości z dokładnością do 10 nm. Stwierdzono, że urządzenie PECS jest szczególnie przydatne do polerowania i trawienia materiałów miękkich, dla których uzyskanie wysokiej jakości powierzchni jest utrudnione i nie zawsze możliwe przy stosowaniu tradycyjnych metod. Ograniczeniem wykorzystania PECS do polerowania i trawienia próbek jest średnica działania wiązki jonów Ar wynosząca maksymalnie 7 mm a efektywnie 5 mm.

EN

The purpose of the work was to specify the opportunities of using and implementing the PECS machine from Gatan - USA. The PECS allows removing tarnishes and scratches and precise etching, both very delicate - required for the highest magnifications, and very deep - for Iow magnifications, as well as depositing carbon and metal layers with the reguired, precisely defined thickness. Etching and cleaning of microsections and depositing and removing layers with required thickness with accuracy of up to 10 nm was carried aut. The PECS was found to be particularly useful for polishing and etching soft materials for which obtaining high-guality surface is hindered and not always possible when using conventional methods. The restriction of using PECS for polishing and etching samples is the diameter of Ar ion beam operation, which is max 7 mm and effectively 5 mm.