Influence of phosphorous and boron on dynamic recrystallization and microstructures of hot-rolled interstitial free steel

초록

This paper examines the effects of phosphorous (P) and boron (B) of Nb-Ti added interstitial free (IF) steel on dynamic recrystallization, mechanical properties and microstructures. For this purpose, four Nb-Ti added IF steels that contain different contents of P and B were selected. The dynamic recrystallization behavior was investigated using hot compression testing. Mechanical properties and microstructures of pilot hot-rolled IF steel sheet were analyzed as well using uni-axial tensile test and electron back-scattered diffraction (EBSD) following pilot hot rolling experiment. It has been found that B strongly retarded dynamic recrystallization of the IF steel in the temperature range of 900-1100 degrees C. However, P did not delay dynamic recrystallization at 1100 degrees C. The effect of P on dynamic recrystallization was less than that of B. EBSD analysis revealed that absence of P and B induced fine ferrite grain size and many high angle grain boundaries. The ferrite grain size of P and B free IF steel was 46.4% smaller than that of IF steel having 0.1% of P and 0.001% of B. (c) 2005 Elsevier B.V. All rights reserved.

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