Studium tepelných kapacit ocelí metodou DSC

Abstract

DSC method (Differential Scanning Calorimetry) is one of the thermal analysis methods which is suitable for studying the thermodynamic properties of metallic systems. In this thesis the heat capacities of two real steels grades in the solid phase under strictly defined conditions for controlled heating were studied. Thermal analysis and calorimetric methods are described in detail in the theoretical part. There are also described computational capabilities for determination of the heat capacities especially in metallic systems. The experimental part of the work is focussed primarily on extensive and time-consuming experiments using high-temperature calorimeter Setaram MHTC 96 (Multi High Temperature Calorimeter) with 3D DSC sensor. The experiments were supported by theoretical calculations using software ThermoCalc (CALPHAD method) and also using Neumann-Kopp rule. Further the work was focused on statistical evaluation of the measuring device capability. Factors which may influence the experimental results obtained by DSC method were studied. These factors include the heating rate and the size of the analyzed sample. Experimentally acquired heat capacity ("Apparent Heat Capacities") of real steels grades were confronted with the calculated theoretical data and with data reported in the available literature.