Fig. 1. EBSD-reconstructed microstructure of initial sample subjected to solid solution treatment at 1573 K for 30 min.

Fig. 2. EBSD-reconstructed microstructures of samples A (a) and B (b), where the colored and gray regions correspond to δ and γ phases, respectively. In δ phase, the white thin lines and thick lines represent low angle grain boundaries (LAGBs) and high angle grain boundaries (HAGBs) respectively; In γ phase, the blue thin lines, blue thick lines, and red lines represent LAGBs, HAGBs, and twin boundaries (TBs), respectively.

Fig. 3. Misorientation distribution in δ (a, c) and γ (b, d) phases of samples A (a, b) and B (c, d).

Fig. 4. Deviation from exact K-S OR in both samples.

Fig. 5. Distributions of grain boundary planes in δ (a, b) and γ (c, d) phases of samples A (a, c) and B (b, d).

Fig. 6. Distributions of grain boundary planes for <111> misorientation grain boundaries, λ(N), plotted in stereographic projection along [001] with misorientation of 10.53°/[11?1ˉ] (a), 49.47°/[???1ˉ?1ˉ?1] (b) and 60°/[11?1ˉ] (c) in γ phase of sample A.

Fig. 7. Distributions of grain boundary planes for <110> misorientation grain boundaries, λ(N), plotted in stereographic projection along [001] with misorientation of 10.53°/[0$\bar{1}\bar{1}$] (a), 49.47°/[011] (b) and 60°/[011] (c) in γ phase of sample A.

Fig. 8. Distributions of grain boundary plane normals for boundaries with different misorientation angles and axes in γ phase of sample A.

Fig. 9. Distributions of grain boundary planes for <111> misorientation grain boundaries, λ(N), plotted in stereographic projection along [001] with misorientation of 10.53°/[11$\bar{1}$] (a), 49.47°/[$\bar{1}\bar{1}$1] (b) and 60°/[11$\bar{1}$] (c) in γ phase of sample B.

Fig. 10. Distributions of grain boundary planes for <110> misorientation grain boundaries, λ(N), plotted in stereographic projection along [001] with misorientation of 10.53°/[0$\bar{1}\bar{1}$] (a), 49.47°/[011] (b) and 60°/[011] (c) in γ phase of sample B.

Fig. 11. Distributions of grain boundary plane normals for boundaries with different misorientation angles and axes in γ phase of sample B.

Fig. 12. Distributions of phase boundary planes with K-S OR in samples A (a) and B (b).