The knowledge of the solidus and liquidus temperatures of the real-steel grades is one of the most important technologicalfactors – especially when dealing with the processes of casting and solidification. These temperatures are critical parameters forproper settings of the models (physical or numerical) or in the final stage of an applied research of a real process. A correctsetting of a production technology is significantly affecting the final quality of the as-cast steel (billets or ingots). Therefore, thispaper is devoted to discussing the findings obtained during a utilization of dynamic thermal-analysis methods to identify thesolidus and liquidus temperatures applicable to commercially produced steels. The results obtained with a differential thermalanalysis (DTA) for three steel grades and with 3D differential scanning calorimetry (3D DSC) for two steel grades are comparedwith the results of the selected equations commonly used for liquidus and/or solidus temperature calculations. The calculationsobtained with the Computherm SW for the discussed steels were also realized.It can be stated that the equilibrium liquidus and solidus temperatures obtained with the above-mentioned methods for each steelgrade differ. The differences between the calculated results, the thermodynamic calculations and thermal-analysis results arevery unpredictable and vary individually for different steels. These differences are not marginal (tens of Celsius degrees). So, itis sometimes suitable to combine several methods for a proper determination of the liquidus and solidus temperatures for acorrect setting of a steel-making process or its modelling. The best solution for a technological process is to obtain the liquidusand solidus temperatures for a concrete-steel grade from a given steelmaking practice – a thermal analysis of a concrete-steelgrade is a possible way.
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