Interfacial Segregation in Ultra-Low Carbon Steels

The purpose of our study is to analyze the grain boundary chemistry of ultra-low carbon steels. These alloys contain many elements and it is necessary to know which of them are free in the matrix. Therefore, we have made a preliminary study of surface segregation. For Interstitial Free (IF) Ti steel, the segregated elements are P, S and Ti. In addition to these elements, carbon is observed in IF Ti-Nb steel. The attractive (Ti-P, Ti-S) and repulsive (C-P, C-S) interactions are clearly revealed. The free enthalpies of surface segregation are evaluated taking into account the precipitation of each element.