摘要
利用单道次热压缩实验,在Gleeble-3500型热模拟机上研究新型贝氏体轴承钢在变形温度900~1200℃,应变速率0.01~5 s^-1,压缩变形量为60%条件下的热变形行为,获得了真应力-真应变曲线。对压缩后的试验钢进行了微观组织分析,建立了其基于峰值应力的本构方程及动态再结晶动力学模型。结果表明:在温度和应变速率的影响下,材料发生了动态再结晶。从显微组织可以看出,变形温度1100℃,应变速率0.5 s^-1时微观晶粒尺寸较为均匀细化。本构模型的计算值与实测值的线性相关系数R2为0.96,呈现出良好的线性关系。根据热变形材料的特征参数,建立了动态再结晶动力学模型,计算值曲线与散点实测值基本吻合,验证了模型的正确性。根据真应变为0.6的应变速率敏感性指数m分布图,获得材料最佳热加工参数为温度950~1150℃,应变速率0.2~0.5 s^-1。
The single pass hot compression test was carried out on Gleeble-3500 thermal simulator to study the hot deformation behavior of the new bainite bearing steel with deformation temperature of 900-1200℃,strain rate of 0.01-5 s^-1,and deformation amount of60%,and the true stress-true strain curves were obtained.The microstructure of the compressed test steel was analyzed,and the constitutive equation and the dynamic recrystallization kinetic model were established based on the peak stress.The results show that with the influence of temperature and strain rate,the material undergoes dynamic recrystallization.It can be seen from the microstructure that when the deformation temperature is 1100℃and the strain rate is 0.5 s^-1,the microscopic grain size is uniform and refined.The linear correlation coefficient R2 between the calculated value and the measured value of the constitutive model is 0.96,showing a good linear relationship.According to the characteristic parameters of the hot deformation material,the dynamic recrystallization kinetics model was established.The curve of calculated value is basically consistent with the scatter of measured value,which verifies the correctness of the model.According to the distribution map of strain rate sensitivity index m with true strain of 0.6,the optimal hot processing parameters of the material are obtained:deformation temperature is 950-1150℃and strain rate is 0.2-0.5 s^-1.
作者
张治红
彭文飞
李淑欣
王洪娟
ZHANG Zhi-hong;PENG Wen-fei;LI Shu-xin;WANG Hong-juan(Faculty of Mechanical Engineering&Mechanics,Ningbo University,Ningbo 315211,China;Part Rolling Key Laboratory of Zhe Jiang Province,Ningbo 315211,China;Ningbo Daer Machinery Technology Co.,Ltd.,Ningbo 315206,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2020年第7期158-167,共10页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(51405248)
浙江省自然科学基金资助项目(LY18E050006)
宁波市科技创新2025重大专项(2018B10004,2019B10100)。
关键词
贝氏体轴承钢
热变形行为
本构方程
动态再结晶
bainite bearing steel
hot deformation behavior
constitutive equation
dynamic recrystallization
