Formulas for the Calculation of Temperatures and Concentrations of Carbon Responsible to the Parar Equilibrium of the Main Phases in Medium Sheet Steels

摘要

With the help of the Thermo-Calc software package, arrays of calculated data were created for carbon concentrations in ferrite and austenite, corresponding to the para-equilibrium of these phases and their para-equilibrium with cementite, as well as for the corresponding temperatures Ai and A3. Marked arrays were obtained in wide temperature ranges for ranges of carbon concentrations and the most important substitution alloying elements (Mn; Si; Cr; Ni; Mo), covering the respective ranges for medium carbon and moderately alloyed steels. Analytical formulas were developed on the basis of the reference data arrays for calculating para-equilibrium concentrations of carbon in ferrite and austenite (depending on temperature and chemical composition), as well as temperatures Ai and A3 (depending on chemical composition), which allow to reproduce with high accuracy the results obtained using Thermo-Calc.