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Microstructure-related properties of explosively welded multi-layer Ti/Al composites after rolling and annealing

Solecka Monika, Mróz Sebastian, Petrzak Paweł, Mania Izabela, Szota Piotr, Stefanik Andrzej, Garstka Tomasz, Paul Henryk

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 1

art. no. e39, 2023

EN

The processes of rolling and annealing of explosively welded multi-layered plates significantly affect the functional properties of the composite. In current research, fifteen-layered composite plates were fabricated using a single-shot explosive welding technique. The composites were then rolled up to 72% to reduce layer thickness, followed by annealing at 625 °C for varying times up to 100 h. Microstructure evolution and chemical composition changes were investigated using scanning electron microscopy equipped with energy-dispersive spectroscopy. The mechanical properties of the composite were evaluated by tensile testing, while the strengths of individual layers near the interface were evaluated by micro-hardness measurements. After explosive welding, the wavy interfaces were always formed between the top layers of the composite and the wave parameters decreasing as the bottom layers approach. Due to the rolling process, the thickness of Ti and Al layers decreases, and the waviness of top interfaces disappeared. Simultaneously, the necking and fracture of some Ti layers were observed. During annealing, the thickness of layers with chemical composition corresponding to the Al3Ti phase increased with annealing time. A study of growth kinetic shows that growth is controlled by chemical reaction and diffusion. The results of micro-hardness tests showed that after annealing, a fourfold increase of hardness can be observed in the reaction layers in relation to the Ti, while in relation to Al, the increase of hardness is even 15 times greater.

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Analiza kalibrowania walców do walcowania szyny kolejowej MAV48

Szota Piotr, Mróz Sebastian, Stefanik Andrzej, Zygmunt Tomasz

Hutnik, Wiadomości Hutnicze

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2022

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Vol. 89, nr 2

13--18

PL

W pracy przedstawiono nowo zaprojektowane kalibrowanie walców przeznaczone do walcowania szyny kolejowej MAV48 w warunkach walcowni D-815 firmy ArcelorMittal Poland S.A. Celem badań było opracowanie projektu kalibrowania walców, który pozwolił na uzyskanie wysokiej dokładności wymiarowej gotowego produktu. Do opracowania nowego kalibrowania walców wykorzystano program typu CAD, a następnie opracowany projekt został zweryfikowany za pomocą obliczeń numerycznych.

EN

A new roll pass design for rolling rail MAV48 shape intended for the production of rails in the conditions of the D-815 rolling mill of ArcelorMittal Poland S.A (Steelworks Królewska) was developed within the study. Aim of researches was develop of roll pass design which allowed obtain a high dimensional accuracy of finished product. For developing the new roll pass design, CAD type graphical software programs were used, and then the developed roll pass design was verified by numerical computation.

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Microstructure and properties of 1050A/AZ31 bimetallic bars produced by explosive cladding and subsequent groove rolling process

Mróz Sebastian, Mola Renata, Szota Piotr, Stefanik Andrzej

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 3

197--211

EN

Within the framework of this study, the 1050A/AZ31 round bimetal bars were produced by the explosive cladding method and subsequent groove rolling process. LM/SEM investigation shown that by proper selection of the explosive cladding parameters (mainly initial distance between 1050A tube and AZ31 core and detonation velocity) it is possible to produce 1050A/AZ31 feedstocks without a continuous layer of Mg–Al intermetallic phases on the interface between joined materials. The experimental tests of the groove rolling process of 1050A/AZ31 bars were supplemented with a theoretical analysis using FEM-based numerical modelling. Based on the test results obtained, it was found that the interface of the 1050A/AZ31 bar rolling at a temperature (300 °C) was characterized by the generation of a thin continuous intermetallic layer without cracks. Applying a higher rolling temperature of 400 °C, which is usually used in hot forming processes of Mg alloys, led to the production of a thicker intermetallic layer, which cracked during the rolling process as a result of deformation. Strength of the fabricated bimetal joints was high, they did not delaminate during shear tests.