Thermodynamic Analysis of Precipitation Behaviors in Hot-Rolled Ti-stabilized Interstitial-Free Steel Sheets

Abstract

Thermodynamic calculations were performed on the precipitation behavior in the hot-rolled Ti-stabilized Interstitial Free (IF) steel sheets. By combining the thermodynamic parameters of Ti₄C₂S₂ evaluated by first-principles calculations with previously reported parameters, parameters were developed that allow the calculation of the precipitation behavior of IF steels during hot rolling. The calculated precipitation behavior using those thermodynamic parameters is in relatively good agreement with the TEM observation results in hot-rolled IF steel sheets. The results of thermodynamic calculations suggest that the precipitation behavior of IF steel sheets during hot rolling depends on the amounts of Mn. These results are considered to be due to the decreased excess S in steel sheets as a result of the increase in precipitation of sulfides containing Mn.