The true stress–strain curves and constitutive equations of 347H austenitic stainless steel were obtained via high temperature compression tests with the temperature range of 850 °C-1250 °C and the strain rate range of 0.01 s⁻¹–10 s⁻¹. We have studied the microstructure evolution and nucleation mechanism of dynamic recrystallization by the electron backscatter distribution technique (EBSD), and the results show that the process of dynamic recrystallization consists of nucleation and growth. At high strain rate (10 s⁻¹) and low temperature (< 1150 °C), the grain size increases with the increase of temperature, while the deformed grain gradually transform to recrystallized grain. When the temperature reaches 1150 °C, the complete dynamic recrystallization occurs and the volume fraction of recrystallized grains reaches the maximum. In addition, the necklace structure has confirmed the existence of discontinuous dynamic recrystallization, while the transition from low-angle grain boundaries to high-angle grain boundaries has confirmed the existence of continuous dynamic recrystallization.

通过高温压缩试验获得了347H奥氏体不锈钢的真应力-应变曲线和本构方程，温度范围为850℃～1250℃，应变速率范围为0.01 s ^-1 ～ 10 s ^-1。我们利用电子背散射分布技术（EBSD）研究了动态再结晶的微观组织演变和形核机制，结果表明动态再结晶过程包括形核和生长。在高应变率 (10 s ^-1）和低温（< 1150 ℃），晶粒尺寸随着温度的升高而增大，而变形晶粒逐渐转变为再结晶晶粒。当温度达到1150℃时，发生完全的动态再结晶，再结晶晶粒的体积分数达到最大值。此外，项链结构证实了不连续动态再结晶的存在，而从低角度晶界向高角度晶界的转变证实了连续动态再结晶的存在。