Effect of deformation heat in the laboratory hot rolling quantified by temperature scanners and modelling based on FEM

Ivo Schindler, Tomáš Kubina, Petr Bílovský, Milan Heger, Miroslav Legerski

VŠB – Technical University of Ostrava, Faculty of Metallurgy and Materials Engineering,,Institute of Modelling and Control of Forming Processes,17. listopadu 15, 708 33 Ostrava, Czech Republic.

DOI:

https://doi.org/10.7494/cmms.2009.2.0229

Abstract:

The capability to measure the surface temperature of relatively small samples plays the key role in conditions of the laboratory hot rolling. The situation is complicated by a small homogeneity of the temperature field, as well as a relatively high speed of movement of the rolling stocks, in combination with their limited length. The installation of two temperature scanners LANDSCAN, working with the scanning speed 100 Hz in a parallel way, on the brackets above all three roller tables of the laboratory rolling mill TANDEM made it possible to register effectively surface temperatures of the samples, moving in an arbitrary place. Only the values of maximum temperatures of particular lines are sent from the temperature scanners to the control computer of the mill TANDEM. Another computer records and processes the whole surface-temperature maps. By means of the original software method a large volume of transferred data was minimized and the control computer records only the time course of maximum temperatures and detects passing the rolling stock beneath both scanning heads. This experimental method was used in monitoring of temperature changes during the high-reduction hot rolling of the plain-carbon steel with different speed. The measured data served for a set up of the dependence between a change of the surface temperature of the rolling stock during its deformation and the corresponding strain rate. The samples quenched just after the deformation into the water underwent the metallographic analyses. The etching to the initial austenitic grain brought the valuable information about the influence of the deformation heat on the kinetics of the metadynamic recrystallization and the structural characteristics. The obtained results are on the whole compatible with the data calculated by means of the exacting mathematical modelling on the basis of FEM. The comparison of the results of the mathematical simulations and the measured temperature values confirmed that for the achievement of more accurate results it is suitable to substitute into the FEM-based software the more precise constants gained by physical measurements.

Cite as:

Schindler, I., Kubina, T., Bílovský, P., Heger, M., & Legerski, M. (2009). Effect of deformation heat in the laboratory hot rolling quantified by temperature scanners and modelling based on FEM. Computer Methods in Materials Science, 9(2), 189 – 194. https://doi.org/10.7494/cmms.2009.2.0229

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