Experimental Study and Modeling of the P

An original model for the precipitation of non-metallic inclusions during the solidification of steel has been developed at IRSID. This study aims to analyze sulphide precipitation in various steel grades including plate grades and bearing steels, through experimental methods on laboratory samples quenched from a partially solidified state. The methodology combines microsegregation equations with equilibrium conditions that correspond to the interactions between liquid steel and different types of inclusions such as oxides, sulphides, nitrides, and carbides within a general multiphase equilibrium code. The results demonstrate that the computed compositions of sulphides, specifically (Mn, Fe)S or (Mn, Fe, Cr)S, align closely with experimental findings. Furthermore, the model effectively characterizes the precipitation of oxide inclusions in semi-killed high-carbon steels, showcasing precise predictions for the heterogeneous population of oxide inclusions formed during various stages of the industrial processing. The implications of this research are fundamental for controlling and optimizing the cleanness of steel, essential for its mechanical and fatigue properties, and provide insights into targeted applications where specific inclusion types may enhance material performance.