Synergic Evolution of Microstructure-Texture-Stored Energy in Rare-Earth-Added Interstitial-Free Steels Undergoing Static Recrystallization

Abstract

Synergic evolution of microstructure-texture-stored energy in interstitial-free (IF) steels has been investigated to elaborate the effect of dissolved rare-earth (RE) elements on static recrystallization. Grain size, texture fraction and geometrically necessary dislocation distribution of IF steel samples annealed for different times were compared, suggesting that RE elements could postpone recrystallization nucleation but accelerate grain coarsening. The visco-plastic self-consistent model was primarily adopted and verified, then used to calculate the relative activities of different slip systems. It was proved that the compatible deformation of IF steels was very sensitive to dissolved RE elements, in particular the {110} 6 <111> 2 slip systems became extremely inactive, leading to an α-fibre textures rich configuration of RE-IF steels. Although both IF steels have the same stored energy sequence of which γ-fibre takes precedence in nucleation followed by α-fibre, the nucleation rates of α/γ-fibres driven by the reduced stored energy slowed down in RE-IF steels. Further nucleation-path analyses revealed that shear bands within γ-fibre mainly sacrificed for grain nucleation of {111}<110> orientation, while α-fibre especially prior grain boundaries therein preferred supplying nucleation sites for {554}<225> grains, which accounting for the competitive growth of γ-fibre textures in RE-IF steels rather than being dominated by a single orientation. After grain growth, the major texture of Normal-IF steels had been transferred to {554}<225> from {111}<110>, while {554}<225> in RE-IF steels still inherited the orientation advantage and grew up rapidly, thus inducing the grain coarsening. As this work offers a significant understanding of RE microalloying effect on static recrystallization, it will provide references for alloy design and industrial application of IF steels.

Role of Cerium on the Intricacies of Deformed State and Softening Mechanisms of Low‐Carbon Steels

“…steels, [3,6,[10][11][12]16,32] whereas the RE-added ones have received very limited attention. [33][34][35] However, most of the literature on cold rolling and annealing of RE-added steels have considered the intercritical or austenitic domain to be an annealing temperature domain. [10,[33][34][35] Wan et al [36] reported that the addition of 0.0066 wt% RE element in nonoriented steels developed favorable grain size and orientations after cold rolling and annealing, suitable for its application.…”

“…[33][34][35] However, most of the literature on cold rolling and annealing of RE-added steels have considered the intercritical or austenitic domain to be an annealing temperature domain. [10,[33][34][35] Wan et al [36] reported that the addition of 0.0066 wt% RE element in nonoriented steels developed favorable grain size and orientations after cold rolling and annealing, suitable for its application. Shi et al [10] and Zhu et al [37] demonstrated that the RE-modified cold-rolled low-carbon steels altered the micro-orientation relationship between the matrix and the newly formed grains after annealing, in contrast to steels without RE.…”

“…steels, [ 3,6,10–12,16,32 ] whereas the RE‐added ones have received very limited attention. [ 33–35 ]…”

“…[ 38,39 ] Zhao et al [ 40 ] reported that after cold rolling and annealing, the Ce‐added steels demonstrated uniform grain size distribution and comprehensively better performance than those without Ce. Further, Liu et al [ 34 ] argued that RE elements could delay the nucleation of recrystallized grains during annealing and subsequently expedite grain coarsening.…”