He Daoguang, Chen Shibing, Lin Yongcheng, Yan Xintao, Liu Guan
School of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China.
State Key Laboratory of Precision Manufacturing for Extreme Service Performance, Changsha 410083, China.
Materials (Basel). 2023 Sep 13;16(18):6192. doi: 10.3390/ma16186192.
Isothermal deformation experiments of the Hastelloy C276 alloy were executed using the Gleeble-3500 hot simulator at a temperature range of 1000-1150 °C and a strain rate range of 0.01-10 s. Microstructural evolution mechanisms were analyzed via transmission electron microscope (TEM) and electron backscatter diffraction (EBSD). Results reveal that the influences of hot compression parameters on the microstructure variation features and flow behaviors of the Hastelloy C276 alloy were significant. The intense strain hardening (SH) effects caused by the accumulation of substructures were promoted when the strain rates were increased, and true stresses exhibited a notable increasing tendency. However, the apparent DRV effects caused by the annihilation of substructures and the increasingly dynamic recrystallization (DRX) behaviors occurred at high compressed temperature, inducing the reduction in true stresses. In addition, a physical-based (PB) constitutive model and a long short-term memory (LSTM) model optimized using the particle swarm optimization (PSO) algorithm were established to predict the flow behavior of Hastelloy C276 alloy. The smaller average absolute relative error and greater relation coefficient suggest that the LSTM model possesses a higher forecasting accuracy than the PB model.
使用Gleeble-3500热模拟试验机在1000-1150°C的温度范围和0.01-10 s⁻¹的应变速率范围内对哈氏合金C276进行了等温变形实验。通过透射电子显微镜（TEM）和电子背散射衍射（EBSD）分析了微观组织演变机制。结果表明，热压缩参数对哈氏合金C276的微观组织变化特征和流变行为影响显著。应变速率增加时，亚结构的积累导致强烈的应变硬化（SH）效应增强，真应力呈现明显的上升趋势。然而，在高温压缩时，亚结构的湮灭引起明显的动态回复（DRV）效应以及动态再结晶（DRX）行为的增加，导致真应力降低。此外，建立了基于物理的（PB）本构模型和使用粒子群优化（PSO）算法优化的长短期记忆（LSTM）模型来预测哈氏合金C276的流变行为。平均绝对相对误差较小且相关系数较大表明LSTM模型比PB模型具有更高的预测精度。
