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Of all publications in the section: 2
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Article
Kubina T., Aksenov S. A. Hutnické listy. 2011. No. 4. P. 88-91.

The results concern roll pass design for rolling a round bar of a 20mm diameter from a 55mm diameter input. Concerning materials, this roll pass design must cover a wide range of steels, from low-carbon micro-alloyed steels to stainless steels. The roll pass design proposal takes into consideration lower plasticity of certain steels. The comparison was enabled by suggesting two roll pass designs. The classical oval-round roll pass design, where the maximum extension coefficient is set to 1.55 in oval and 1.22 in round grooves. The second roll pass design uses a combination of smooth part of the roll (curves) and round roll passes. Distribution of the extension coefficient in individual passes is similar to that of oval-round series. The paper also compares values of energy-force parameters calculated analytically using the method of finite elements. If we compare the distribution of temperature, stress and size of the grain, it is proved that the oval-round roll pass designs are the best as far as the balanced distribution of the above-mentioned values is concerned. The roll pas design combining smooth part of the roll with a round part does not achieve such balance. However, its advantage lies in far lower requirement for the needed length of the working part of the roll. Five passes are carried out on the smooth part of the roll, which considerably cuts down the required length of the roll body. Therefore it is this variant that will be used in the laboratory of wire rolling created within the project RMSTC.

Added: Apr 12, 2012
Article
Aksenov S. A., Chumachenko E. N., Logashina I. V. et al. Hutnické listy. 2010. No. 4. P. 110-113.
The technological process considered in the paper is a rolling of a round bar in roughing mill group, which consist of four passes. The computer simulation of the process shows that the local plastic deformations occurring in the material are extremely large, which may lead to the appearing of defects. The investigations performed, led to the development of new roll pass design, which almost halved the maximum value of local plastic deformation in the material during rolling. Since full 3D finite element method (FEM) based models needs significant amount of computer memory and CPU time, it was not suitable for the performed study, which involves a bulk of simulations with different initial conditions. Therefore, the quick algorithms for simulation of rolling processes, which based on so-called “2.5D” method, have been used. This method, due to number of simplifications, is significant faster than conventional 3D FEM, and at the same time it allows to reach good accuracy of the model. The developed computer software SPLEN(Rolling) which implements “2.5D” FEM simulations was applied for computations and analysis of the results. This software is able to predict the shape evolution of rolled material, as well as distributions of strain, strain rate and temperature within the volume of deformation zone. It has been shown that computer simulation based on “2.5D” FEM implemented in SPLEN(Rolling) software can be efficiently used for roll pass design development and optimization.
Added: Apr 12, 2012