DATA PROCESSING OF MEASURED SURFACE TEMPERATURES OF CONTINUOUSLY CAST BILLETS and blooms TO VERIFY THE NUMERICAL SOLIDIFICATION MODEL

Abstract

Numerical models of solidification and cooling of continuously cast billets or blooms are used both in research and in operational conditions to predict solid shell thickness, metallurgical length, solidification rate etc. The numerical model must be verified according to real values of quantities. Although several different quantities can be used to verify the model, most often the models are verified by comparing the calculated and measured surface temperatures of the strand in the secondary and tertiary cooling zones. The casting process is influenced by a number of known and hidden parameters, often time-varying, which are reflected in the measured surface temperatures, but which cannot be incorporated into the model due to a lack of information to define the exact boundary conditions. For the purposes of model verification, it is therefore necessary to revise the measured data. It is not enough to use only mathematical methods to process data without knowledge of the casting process, because uncertainties and temperature fluctuations have different and often difficult to detect causes. The article deals with sources of temperature uncertainties and fluctuations and methods of extraction of relevant values from measured signals.