Wyniki wyszukiwania - BazTech

1

Multiphase Ausformed Austempered Ductile Iron

Soliman M., Palkowski H., Nofal A.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 3

1493--1498

EN

Ductile iron was subjected to a total true strain (φt) of 0.3 either by applying φt in the austenite region or by apportioning it through applying a true strain of 0.2 in the austenite region before quenching to austempering temperature (TA) of 375°C, where a true strain of 0.1 is applied (ausforming). Additionally, two types of matrices were produced in the ductile iron, namely ausferritic and ferritic-ausferritic matrices. The ferrite is introduced to the matrix by intercritical annealing after austenitization. Dilatometric measurements as well as microstructure examination showed a fast ausferrite transformation directly after applying φA and that the introduction of ferrite to the matrix resulted in a remarkable acceleration of the ausferrite formation. The transformation kinetics, microstructure evolution, hardness and compression properties are studied.

2

Development of the low temperature bainite

Soliman M., Palkowski H.

Archives of Civil and Mechanical Engineering

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2016

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Vol. 16, no. 3

403--412

EN

The possibility of obtaining steels with nano-size plates of bainitic-ferrite by isothermal transformation at low temperature is set forth. These steels have attracted great interest due to their excellent combination of strength, toughness, and ductility. In further investigations, the composition and the processing methods of these steels are adjusted to: (1) Optimize their technological properties with regard to mechanical behavior, weldability and formability. (2) Accelerate their transformation kinetics. (3) Minimize/eliminate the need for expensive alloying elements. (4) Lower the martensite start temperature (Ms) either by thermo-mechanical processing or by modifying the bainite transformation stage. Suppressing Ms is of particular importance in steels with relatively low carbon content; that is to allow for bainite formation at low temperature. Furthermore, many reports addressed some technological aspects like fatigue behavior, wear resistance and bake hardenability. This article presents an overview of the so far studied alloying strategies and processing methods adopted for developing the low temperature bainite together with addressing some examined technological themes. The paper is engrafted in relevant sections with new results of the authors that are not published before. One of these results is that the low temperature bainite possesses a very strong bake hardening potential.

3

Deep drawing properties of lightweight steel/polymer/steel sandwich composites

Sokolova O. A., Kuhn M., Palkowski H.

Archives of Civil and Mechanical Engineering

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2012

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Vol. 12, no. 2

105--112

EN

Due to the wide range of different properties – such as high strength, stiffness, high damping capacity, vibration resistance and the lightweight – metal/polymer/metal sand- wich composites find their application as various body-parts in the automotive industry. Nevertheless the forming potential of layered sandwiches under different loading is not well studied. In this research the formability of 316L/PP–PE/316L sandwich composites with different sample size and core thickness was studied for the deep drawing process using two flat punches of different size and shape. It could be stated that the forming behaviour of the three layered sandwiches is strongly influenced by the geometry of the punch and the core thickness. The results were analysed photogrammetrically and metallographically.

4

Wyznaczanie pól odkształceń w procesie walcowania pielgrzymowego rur miedzianych i aluminiowych

Palkowski H., Pociecha D., Osika J., Świątkowski K.

Rudy i Metale Nieżelazne

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2010

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R. 55, nr 11

770-775

PL

W niniejszym artykule zaprezentowano wyniki pomiarów odkształceń w rurach aluminiowych i miedzianych, uzyskanych na drodze walcowania pielgrzymowego. Rury aluminiowe walcowane były, w modelowej walcarce pielgrzymowej nowej generacji, rury miedziane na przemysłowej walcarce pielgrzymowej KPW75VMRK. Do pomiarów wykorzystano optyczny system pomiarowy ARGUS, niemieckiej firmy GOM. Po uprzednim elektrochemicznym naniesieniu siatki na powierzchni badanej rury, zostaje ona odkształcona. System ARGUS wylicza odkształcenia, wykorzystując fotografie rury z odkształconą siatką. Otrzymane wyniki służyć mają do weryfikacji poprawności działania metody stereofotogrametrycznej, używanej do pomiarów odkształceń w modelowej walcarce pielgrzymowej oraz do otrzymania rozkładu naprężeń w kotlinie walcowniczej walcarki pielgrzymowej.

EN

The paper presents results of strain measurement in aluminium and copper tubes, obtained by cold pilger rolling method. Aluminium tubes were rolled, using in the new generation pilger roller model mill, and a copper tubes were rolled in an industrial KPW75VMRK pilger mill. For the measurements, an optical measuring system ARGUS was used, produced by German company GOM. Firstly, on the tube surface the grid was made, using electrochemical method, then the tube was deformed in pilger mill. The ARGUS system calculates strains, using photographs of the tube with deformed grid. Results, which are used to stereo-photogrammetric method verification, were obtained. This method is used to strain measurement, in pilger roller model mill, and to stress distribution calculation, in pilger mill roll gap.

5

Analysis of Material Deformation during the New Cold Tube Rolling Process Realized on the New Generation of Pilger Mills

Osika P., Palkowski H., Świątkowski K., Pociecha D., Kula A.

Archives of Metallurgy and Materials

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2009

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Vol. 54, iss. 4

1239-1251

EN

The wear of tools in tube cold pilger process should be taken into consideration during process design. The working life will be longer as well as the regeneration of tool easier when the wear of tool is uniform. To obtain the uniform wear distribution the unit pressures along the working zone should be also uniform. The method of measuring of deformation distributions along the working zone were used to obtain the distribution of unit pressure. In the paper the methods of measuring of the deformation distribution along the working zone were presented. FEM and FDM methods were used for calculations of the deformation distribution along the working zone. The direct measuring of markers displacement was presented, using the stereophotogrammetric method.

PL

Podczas projektowania narzedzi wykorzystywanych w procesie walcowania pielgrzymowego rur, nalezy uwzglednic ich zuzycie. Równomierne zuzycie narzedzi przedłuza ich zywotnosc, jak równiez ułatwia pózniejsza regeneracje. W tym celu powinno zapewnic sie równomierny rozkład nacisków jednostkowych wystepujacych w kotlinie walcowniczej. Ze wzgledu na charakter procesu, bezposredni pomiar nacisków jednostkowych jest niemozliwy, dlatego mozna wykorzystac dane dotyczace odkształcen walcowanej rury. W niniejszej pracy zaprezentowano sposoby wyznaczania odkształcen wystepujacych w materiale podczas walcowania pielgrzymowego. Proponowane sposoby [6], opieraja sie o Metode Róznic Skonczonych oraz o Metode Elementów Skonczonych. Zaprezentowano równiez sposób bezposredniego wyznaczania przemieszczen z pomiaru współrzednych punktów przed i po wykonaniu odkształcenia. W tym celu wykorzystano metode stereofotogrametryczna, umozliwiajaca uzyskanie przestrzennego rozkładu punktów na badanej powierzchni.