Study on Thermal Deformation of as-Cast S32101 Economical Duplex Stainless Steel

This study investigates the hot deformation behavior of cast S32101 duplex stainless steel through hot compression tests conducted at temperatures ranging from 950 °C to 1200 °C and strain rates of 0.01–10 s–1, with a true strain of 0.916. Electron backscatter diffraction (EBSD) was used for characterization to explore the thermodynamic behavior, hot deformation map, and microstructural evolution during the deformation process. True stress-strain curves were generated under various deformation conditions, and a high-precision Arrhenius-based constitutive model was developed. Microstructural analysis revealed that at 1100 °C/10 s–1 and 1150 °C/0.01 s–1, both ferrite and austenite phases deformed uniformly. At 1150 °C, dynamic recryst­allization (DRX) was promoted in the austenite phase as the strain rate increased from 0.01 s–1 to 10 s–1. At 950 °C/0.1–10 s–1, severe deformation occurred in the microstructure. The primary recovery mechanisms for the austenite phase at low and high temperatures were dynamic recovery (DRV) and dynamic recrystallization (DRX), respectively. The ferrite phase softened through continuous dynamic recrystallization. A dynamic material model (DMM) hot-deformation map was established, revealing the optimal processing windows to be 950–1200 °C/0.01 s–1 and 1100 °C/0.01–10 s–1.