Fig. 1 Schematic diagram of a ST, b STA, c STCR, d STCRA samples. Black dots represent the ω-phase after aging, and black lines indicate the twins induced by pre-cold rolling

Fig. 2 Deformation microstructure of a half-cut 4% tensile-strained ST sample. Optical micrographs are taken at four different positions (black rectangles) along tensile direction from center to edge for analyzing the area fraction of twins. The horizontal direction is parallel to the tensile direction

Fig. 3 Optical micrographs for a ST, b STA, c STCR, d STCRA samples. The rolling plane is observed, and the horizontal direction is parallel to the RD

Fig. 4 XRD profiles for a ST, b STA, c STCR, d STCRA samples. The rolling plane is analyzed

Fig. 5 a TEM dark-field image and b selected area electron diffraction pattern for STA sample. Bright area in a is isothermal ω-phase and dark area is β-matrix. Zone axis is parallel to [011]β. c EBSD inverse pole figure and d corresponding boundaries map for STCRA sample. Red and gray lines in d are {332} < 113 > twin and grain boundaries, respectively

Fig. 6 a Nominal stress-strain curves, b true stress (σ)-true strain (ε) curves and work hardening rate (dσ/dε) curves, c correlation between work hardening rate and true stress of the ST, STA, STCR, and STCRA samples

Fig. 7 Optical micrographs of the fractured a ST, b STA, c STCR, d STCRA samples

Fig. 8 EBSD maps of microstructures for a, b the STCR sample, c, d the 4% tensile-strained STCRA sample. a, c inverse pole figures for the RD, b, d boundaries delineated by red lines represent the {332} < 113 > twins. The rolling plane is observed, and the horizontal direction is parallel to the RD

Fig. 9 Uniform elongation as a function of yield strength for STCR (solid circle) and STCRA (solid triangle) samples along with those of ST and STA samples and the previous data [5] (open circles)

Fig. 10 Plots of {332} < 113 > twin density versus plastic strain in STCR sample (solid circles) and 4% tensile-strained STCRA sample (solid triangle) along with those of previous data [5] (open circles)

Fig. 11 Deformation microstructures of a, b the STCR sample, c, d the 4% tensile-strained STCRA sample. a, c original optical micrographs, b, d corresponding analyzed images by software. The black lines represent the grain boundaries and twin boundaries, and the white area is β-matrix. The rolling plane is observed, and the horizontal direction is parallel to the RD

Fig. 12 Optical micrographs of a STCRA, b 4% tensile-strained STCRA samples. The rolling plane is observed, and the horizontal direction is parallel to the tensile direction