Fig. 1. Schematic of the experimental setup and analyzed regions: (a) schematic of the experimental setup, (b) EBSD analyzed regions, and (c) TEM analyzed regions.

Fig. 2. Compressive true stress-strain curves of samples A and B.

Fig. 3. Temperature rise of sample B: (a) temperature rise detected by the thermocouple, (b) temperature rise of the entire system detected by the infrared imager, (c) temperature rise of sample B detected by the infrared imager, and d temperature rise of the stainless steel electrodes detected by the infrared imager. Simultaneous use of the thermocouple and infrared imager avoided large measurement errors and facilitated the analysis of sample heating mechanisms.

Fig. 4. IPF and PF maps of the hot rolled plate, sample A, and sample B: (a) maps of the hot rolled plate, (b) maps at A1 in sample A, (c) maps at A2 in sample A, (d) maps at A3 in sample A, (e) maps at B1 in sample B, (f) maps at B2 in sample B, and (g) maps at B3 in sample B. A1, A2, A3, B1, B2, and B3 are all shown along the radius, equidistant from the crack to the edge.

Fig. 5. Evolution of the dislocation in the hot rolled plate, sample A, and sample B: (a-d) dislocation in the grains of the hot rolled plate, (e-h) dislocation in the grains of sample A at a 0.2 strain, (i-l) dislocation in the grains of sample B at a 0.2 strain, (m-n) dislocation near the grain boundary of sample A at a 0.2 strain, and (o-p) dislocation near the grain boundary of sample B at a 0.2 strain. Selecting multiple random points for each sample for analysis can effectively improve the statistical results of TEM and increase its reference value.

Fig. 6. Relationship between the crack and hot rolled plate RD: (a) crack direction, grain deformation direction, and precipitates distribution direction of sample A, from the crack to the edge, in the radial direction, (b) crack direction, grain deformation direction, and precipitate distribution directions of sample B, from the crack to the edge, in the radial direction. The optical image reflects the crack direction perpendicular to the hot rolled plate RD. SCP represents a simple compression process and EPC represents electroplastic compression.

Fig. 7. Deformation degree and direction of the sample A and B grains: (a) analysis location map, (b) deformation degree and direction in A-1 of sample A, (c) deformation degree and direction in A-2 of sample A, (d) deformation degree and direction in A-3 of sample A, (e) deformation degree and direction in B-1 of sample B, (f) deformation degree and direction in B-2 of sample B, and (g) deformation degree and direction in B-3 of sample B. Based on the degree and direction of deformation of the grains, the relative magnitude and direction of the stress at different regions in the sample can be qualitatively determined.

Fig. 8. Dislocation accumulation model of simple compression and electroplastic compression: (a) dislocation accumulation in the hot rolled plate, (b) degree of dislocation accumulation increase and broken crystal grains after simple compression, (c) after electroplastic compression, degree of dislocation plugging reduction with no broken crystal grains. The number of dislocations in a single grain was reduced, and the grain size and quantity were not significantly changed. Compared with sample A, fewer grains and a lower dislocation density and degree of accumulation in a single grain resulted in a decrease in the stress and an increase in the plasticity of sample B.

Fig. 9. Φ2 = 45° ODF cross section diagram: (a) Φ2 = 45° ODF cross section diagram of the hot rolled plate, (b) Φ2 = 45° ODF cross section diagram at A1 of sample A, (c) Φ2 = 45° ODF cross section diagram at A2 of sample A, (d) Φ2 = 45° ODF cross section diagram at A3 of sample A, (e) Φ2 = 45° ODF cross section diagram at B1 of sample B, (f) Φ2 = 45° ODF cross section diagram at B2 of sample B, and (g) Φ2 = 45° ODF cross section diagram at B3 of sample B. ODF can more accurately reflect the type and intensity of the texture, which is required for an in-depth analysis.

Fig. 10. Characteristics of the external load and electron wind stress and the rotation law of the crystal grains under the coupled stress field: (a) stress state in different regions during simple compression, (b) relationship between the stress state and grain rotation at A3 in sample A during simple compression, (c) relationship between the stress state and grain rotation at A2 in sample A during simple compression, (d) stress state and grain rotation angle at A3 in sample A during simple compression, (e) stress state and grain rotation angle at A2 in sample A during simple compression, (f) coupled stress field and grain rotation at B3 in sample B during electroplastic compression, and (g) coupled stress field and grain rotation at B2 in sample B during electroplastic compression.

Fig. 11. Texture intensity changes in A1, A2, and A3 of sample A and B1, B2, and B3 of sample B.