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 rolling simulations were carried out on two commercial Ti-Nb stabilized interstitial-free (IF) steels to investigate their how behavior in the ferrite region. The comparison between the measured and predicted stress curves indicated that dynamic recovery was the dominant softening mechanism during axisymmetric compression deformation. The flow stress curves during CSP-warm rolling simulations indicated that static and dynamic recovery dominated the softening process for early passes and an apparent dynamic recrystallization contributed to the flow stress reductions for the last two passes. The microstructural evolution during the simulation confirmed that the very fine quasi-equiaxed ferrite grains obtained could be explained by apparent dynamic recrystallization, which was assisted by dynamic recovery at high temperature and a reduced Nb solute drag. (C) 2001 Published by Elsevier Science Ltd on behalf of Acta Materialia Inc.