The subject of the presented paper is the comparison between experimental and theoretical work concerning the rolling of round bars made of two layers. The charge was made using explosive method. Steel round cores were placed inside cylindrical copper shells and such samples were next exposed to explosion shock wave. Thanks to that, the materials were subjected to high pressure welding. The weld of both metals was very hard and no slide between core and shell was observed during successive rolling. The rolling temperature was 950°C and higher, which for copper is a very elevated level. A coupled thermo-mechanical-microstructural model was used for the simulation of behaviour of both metallic layers. The model has been developed by the author and besides modelling of thermo-mechanical processing, which has been used for the purpose of the current paper, allows the modelling of austenite grain size evolution, pearlite transformation model and microstructural-mechanical properties. The mechanical part of the model uses a generalised plain-strain approach, which simplifies solution, and significantly saves computing time and computer memory requirements without decreasing the accuracy. The complex description of the model presented has been published in Glowacki (1998) and Glowacki (2000). Very similar simulation method can be used for modelling of direct rolling of continuously cast steel. The soft, partially fluid core and the hard solid shell can be considered as two different porous materials. The work presented in this paper is the first step to such a simulation where the comparison with the experimental results are next to impossible because of the extremely high temperature of the material.
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