【作者】 程志诚； 刘宏强； 余伟； 蔡庆伍；

【Author】 Zhi-cheng Cheng;Hong-qiang Liu;Wei Yu;Qing-wu Cai;Institute of Engineering Technology,University of Science and Technology Beijing;Collaborative Innovation Center of Steel Technology,University of Science and Technology Beijing;

【机构】 北京科技大学工程技术研究院； 北京科技大学钢铁共性技术协同创新中心；

【摘要】 预压下是一种改善铸坯心部缺陷的新工艺。在对预压下热变形过程的数值模拟时,材料流变应力模型的构建至关重要。本研究采用Gleeble 3800热模拟实验机对42CrMo钢进行了等温单向热压缩实验,得到了其在5个应变速率(0.001-0.1s-1),7个应变温度(950-1250℃)下的流变应力曲线。结果表明,温度和应变速率对流变应力影响很大,影响具体表现为流变应力随温度上升而下降;随应变速率加快而上升。基于实验结果,分别建立了种基于应变补偿的Arrhenius本构模型和人工神经网络模型,从相关系数等方面将模拟结果与实验结果对比,发现人工神经网络模型模拟精度更高,可用于后续的数值仿真。更多还原

【Abstract】 Reduction pretreatment is a new technique to improve the internal quality by causing plastic deformation in the core and providing the recrystallization energy. In order to reasonably formulate the hot forming process parameters of 42 CrMo steel, the thermal compression experiment of 42 CrMo steel was conducted on Gleeble-3800 thermal-mechanical at 950-1250℃ with the rate of deformation 0.001-0.1 s-1 and the deformation of 60%, and its deformation behavior at high temperature was studied. The influence of flow stress temperature and strain rate of 42 CrMo steel was investigated in this research. Based on the experimental results, the Arrhenius constitutive model of strain compensation is established. Compared with the experimental results, the constitutive equation can be used for subsequent numerical simulation.更多还原