SOLUBILITY PRODUCTS OF TITANIUM SULFIDE AND CARBOSULFIDE IN ULTRA-LOWCARBON-STEELS

The equilibrium precipitation behaviour of Ti stabilised interstitial free steels was studied quantitatively. The solubility products of TIS and Ti4C2S2 in austenite were determined with dissolution experiments . The results are as follows log[Ti][S]=-13975/T+5.43 log[Ti][C](0.5)[ S](0.5)=-17045/T+7.9 The calculated results using these solubility pro ducts agree well with other experimental results of steels not involve d in the dissolution experiments. The solubility products obtained in the current work were compared with other published solubility product s of TIS and Ti4C2S2 using all known experimental data from different sources to the knowledge of the authors, and it was shown that the sol ubility products determined in the current work provided the best fill ings with the experimental results. The influence of reheating time on the precipitation state in the steels was also investigated. It was s hown that at high temperatures (e.g. 1 150 degrees C) equilibrium stat e of precipitates can be reached within one hour during reheating.