Hot Deformation Characteristic and Strain Dependent Constitutive Flow Stress Modelling of Ti + Nb Stabilized Interstitial Free Steel

Author(s)
Sumit Ghosh, Mahesh Chandra Somani, Daria Setman, Suhrit Mula
Abstract

An effort has been made to establish a relation between Zener-Hollomon parameter, flow stress and dynamic recrystallization (DRX). In this context, the plastic flow behavior of Ti + Nb stabilized interstitial free (IF) steel was investigated in a temperature range of 650-1100 degrees C and at constant true strain rates in the range 10(-3)-10 s(-1), to a total true strain of 0.7. The flow stress curves can be categorized into two distinct types, i.e. with/without the presence of steady-state flow following peak stress behavior. A novel constitutive model comprising the strain effect on the activation energy of DRX and other material constants has been established to predict the constitutive flow behavior of the IF steel in both alpha and gamma phase regions, separately. Predicted flow stress seems to correlate well with the experimental data both in gamma and alpha phase regions with a high correlation coefficient (0.982 and 0.936, respectively) and low average absolute relative error (7 and 11%, respectively) showing excellent fitting. A detailed analysis of the flow stress, activation energy of DRX and stress exponent in accord with the modelled equations suggests that dislocation glide controlled by dislocation climb is the dominant mechanism for the DRX, as confirmed by the transmission electron microscopy analysis. Graphic

Organisation(s)
Physics of Nanostructured Materials
External organisation(s)
University of Oulu, Indian Institute of Technology Roorkee
Journal
Metals and Materials International
Volume
27
Pages
2481–2498
No. of pages
18
ISSN
1598-9623
DOI
https://doi.org/10.1007/s12540-020-00827-1
Publication date
08-2020
Peer reviewed
Yes
Austrian Fields of Science 2012
103018 Materials physics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/hot-deformation-characteristic-and-strain-dependent-constitutive-flow-stress-modelling-of-ti--nb-stabilized-interstitial-free-steel(8c00d750-9dba-4b8a-97e1-9617be996950).html