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The texture characteristics of a Ti-IF steel in ferritic hot-rolled (warm-rolled), cold-rolled, and annealed status were studied. The hot bands were obtained by finish rolling in ferrite region, coiling at very low temperature, and then directly annealing in industrial trial. It was found that 001 f g 110 h i dominates at the surface and 111 f g 112 h iis the main component at the midsection in the hot band. The α-fiber at the surface as well as at the midsection intensifies during cold rolling and weakens during annealing, while the changing of γ-fiber depends on the hot band texture during cold rolling, but it absolutely intensifies after a welladvanced state of annealing. Orientations concentrate on 001 f g 110 h i increasingly at the surface and continuously rotate to RD-fiber at the midsection as the reduction increases. The average plastic strain ratio, elongation, and strain hardening exponent measured for the cold-rolled and annealed steel increased with improving annealing temperatures.

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In the present work, the microstructure and texture of non-oriented 3.3% Si steel processed by asymmetric rolling (ASR) and subsequent annealing at different temperatures were compared with those obtained when using traditional symmetric rolling (SR). This work aims to reveal the effect of shear bands introduced by the ASR on the microstructure and texture evolution. The ASR sample reaches a recrystallization fraction of 62% at an annealing temperature of 650 °C, which is 32% higher than that of the SR sample annealed at the same temperature. This can be attributed to the abundant shear bands introduced by the ASR, which serve as the heterogeneous nucleation sites for the recrystallized grains. When increasing the annealing temperature to 750 °C, complete recrystallization could be observed in both asymmetric- and symmetric-rolled samples. When using an annealing temperature of 650 °C, the γ-oriented grains were dominant in the surface layer, while strong Goss-oriented grains could be observed in the center in the ASR sample. This is due to the fragmented small subgrains with different orientations in the surface layer inhibiting the nucleation of Goss- and cube-oriented grains during the annealing. In contrast, numerous Goss- and cube-oriented grains were formed in the surface layer after complete recrystallization when the ASR sample was annealed at a temperature of 750 °C. This may be related to the higher thermal energy, which benefits the nucleation of the Goss- and cube-oriented grains. In addition, ASR significantly increased the strength of η-fiber after complete recrystallization when compared with SR. This work might be helpful to design the rolling and the subsequent annealing processes.

Asymmetric rolling (ASR) is an efficient processing for fabricating ultrafine-grained (UFG) materials. In the present investigation, interstitial-free (IF) steels with the grain size ranged from 500 nm to 500 μm were obtained by asymmetric rolling and subsequent annealing. The evolution of microstructures and mechanical properties of IF steel were studied. Accordingly, the Hall-Petch relationship of IF steel with a wide grain size range was established. It was found that ultimate tensile strength (UTS) corresponds well to the Hall-Petch relationship over the whole grain size range. However, the yield strength (YS) and hardness deviated from the Hall-Petch relationship as the grain size is larger than 100 μm, which is mainly attributed to the slight effect of grain boundary as obstacle on the dislocation movement and/or pile-up under small deformation in coarse grain (CG).

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