Flow stress modeling and warm rolling simulation behavior of two Ti-Nb interstitial-free steels in the ferrite region

Axisymmetric compression tests and compact strip production (CSP) warm roll ing simulations were carried out on two commercial Ti-Nb stabilized interst itial-free (IF) steels to investigate their how behavior in the ferrite reg ion. The comparison between the measured and predicted stress curves indica ted that dynamic recovery was the dominant softening mechanism during axisy mmetric compression deformation. The flow stress curves during CSP-warm rol ling simulations indicated that static and dynamic recovery dominated the s oftening process for early passes and an apparent dynamic recrystallization contributed to the flow stress reductions for the last two passes. The mic rostructural evolution during the simulation confirmed that the very fine q uasi-equiaxed ferrite grains obtained could be explained by apparent dynami c recrystallization, which was assisted by dynamic recovery at high tempera ture and a reduced Nb solute drag. (C) 2001 Published by Elsevier Science L td on behalf of Acta Materialia Inc.