Regulatory mechanism of thermal deformation behavior and microstructure evolution of Alloy31 alloy

Single-pass and double-pass hot compression experiments were conducted on Alloy31 using a Gleeble-3800 thermal simulation tester under varying deformation temperatures (950–1200 °C), strain rates (0.01–10 s −1 ), and deformation amounts (10 %-60 %). The Arrhenius constitutive equation was constructed, yielding a thermal activation energy (Q) of 524999.695 J/mol. Comprehensive analysis of processing maps and microstructures indicated that the optimal hot working window for Alloy31 is 1070–1200 °C (0.01–0.11 s −1 ) and 1150–1200 °C (1–10 s −1 ). The volume fraction of dynamic recrystallization (DRX) increased with rising temperature under both single-pass and double-pass conditions, and was positively correlated with the deformation amount. The fraction of Σ3 twin boundaries showed a positive correlation with both temperature and deformation amount. The relationships among Σ3 n twin boundaries were observed: Σ3 + Σ3 = Σ9, and Σ3 + Σ9 = Σ27. The combined effects of high deformation stored energy, adiabatic heating, and high dislocation density resulted in a higher DRX volume fraction at 10 s −1 . The nucleation mechanisms of discontinuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX) coexisted during the hot deformation of Alloy31. Increasing temperature enhanced the DDRX mechanism while suppressing the CDRX mechanism. Experiments with varying deformation amounts revealed that the CDRX mechanism was most active at 30 % deformation. DDRX, characterized by the bulging and migration of high-angle grain boundaries, served as the primary DRX nucleation mechanism and was predominant at high temperatures. In contrast, CDRX, involving the continuous rotation of subgrains, acted as a supplementary nucleation mechanism promoting DRX and was more likely to occur at lower temperatures. Single-pass and double-pass hot compression experiments were conducted on Alloy31 using a Gleeble-3800 thermal simulation tester under varying deformation temperatures (950–1200 °C), strain rates (0.01–10 s −1 ), and deformation amounts (10 %-60 %). Comprehensive analysis of processing maps and microstructures indicated that the optimal hot working window for Alloy31 is 1070–1200 °C (0.01–0.11 s −1 ) and 1150–1200 °C (1–10 s −1 ). Increasing temperature enhanced the DDRX mechanism while suppressing the CDRX mechanism. Experiments with varying deformation amounts revealed that the CDRX mechanism was most active at 30 % deformation. DDRX, characterized by the bulging and migration of high-angle grain boundaries, served as the primary DRX nucleation mechanism and was predominant at high temperatures. In contrast, CDRX, involving the continuous rotation of subgrains, acted as a supplementary nucleation mechanism promoting DRX and was more likely to occur at lower temperatures.