Role of nanoscale TiC particles in batch annealing of Ti stabilised interstitial free steels

Abstract

The effect of nanoscale TiC precipitates on the annealing texture and mechanical properties of a titanium stabilised interstitial free (Ti-IF) steel in batch annealing has been examined. By pretreating hot rolled Ti-IF steel sheets, materials with different TiC sizes and dispersions are obtained. It is found that the difference in the initial TiC morphology has little effect on the texture and properties of annealed Ti-IF steels. This result deviates from previous findings in the literature regarding the deteriorating effect of fine precipitates on annealing texture in continuous annealing of IF steels. It is believed that the observed deteriorating effect reported in the literature actually results from the pinning effect of solute C atoms from carbide dissolution at high temperature. Batch annealing has a much lower temperature than continuous annealing, so it produces much less carbide dissolution and liberates less solute C atoms into the ferrite matrix, and therefore recrystallisation is little affected.