Comparative Study on Precipitation Behavior and Texture Formation of Ti-IF Steel and Nb+Ti-IF Steel during Batch Annealing

Precipitation behavior and texture formation of the two interstitial-free steels with Nb and without Nb addition during cold rolling-batch annealing process were investigated by using metallographic microscope,scanning electron microscope（SEM）,transmission electron microscope（TEM） and X-ray diffraction（XRD） instrument.The results show that Nb does not significantly improve the recrystallization texture;however,it promotes the formation of TiN,TiC and TiS and increases the number and size of TiN precipitate by increasing the effective solid solubility of Ti in the matrix;as a good grain refiner,Nb inhibits grain growth during coiling and recrystallization annealing;the addition of Nb tends to coarsen the carbonitride precipitates and reduce the volume fraction of the {111}＜110＞ texture component in the γ fiber.