GH4742高温合金热变形过程中动态再结晶动力学研究  

Study on dynamic recrystallization kinetics during hot deformation of GH4742 superalloy

作　　者：张文文[1] 冯阳 李虎成 田强[2] 秦鹤勇[2] 刘鑫刚[1] ZHANG Wen-wen;FENG Yang;LI Hu-cheng;TIAN Qiang;QIN He-yong;LIU Xin-gang(College of Mechanical Engineering,Yanshan University,Qinhuangdao 066004,China;High Temperature Materials Research Division,Central Iron and Steel Research Institute,Beijing 100081,China)

机构地区：[1]燕山大学机械工程学院,河北秦皇岛066004 [2]钢铁研究总院高温材料研究所,北京100081

出　　处：《塑性工程学报》2024年第11期123-130,共8页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(12202375);秦皇岛市科学技术研究与发展计划项目(202401A001)。

摘　　要：为研究GH4742高温合金在热变形过程中的动态再结晶行为,对GH4742高温合金进行了等温压缩实验,研究了变形温度为1050~1140℃、应变速率为0.01~1 s^(-1)、应变为0.18~1.20下的动态再结晶行为,定量分析了各变形条件下试样的显微组织,确定了不同变形条件下的动态再结晶分数。利用经典的动力学和晶粒尺寸模型,建立了GH4742高温合金的动态再结晶动力学模型和动态再结晶晶粒尺寸模型。结果表明,不同变形条件下拟合的动态再结晶动力学曲线均呈“S”型,在较低和较高应变时动态再结晶分数的增长率都很低,而在中等应变时,动态再结晶分数的增长率明显增加。再结晶晶粒尺寸随着温度和应变的增大而增大,随着应变速率的增大而减小。依据所建立的动态再结晶动力学和动态再结晶晶粒尺寸模型,不仅可以为高温合金热加工过程显微组织演化模拟提供参数输入,还可以为优化工艺,进而获得组织均匀的显微组织提供理论依据。To study the dynamic recrystallization behavior of GH4742 superalloy during hot deformation,the isothermal compression tests of GH4742 superalloy were carried out.The dynamic recrystallization behaviors of GH4742 superalloy at deformation temperature of 1050-1140℃,strain rate of 0.01^(-1) s^(-1) and strain of 0.18-1.20 were studied.The microstructure of the samples under different deformation conditions was quantitatively analyzed.The dynamic recrystallization fraction under different deformation conditions was determined.The dynamic recrystallization kinetics model and the dynamic recrystallization grain size model of GH4742 superalloy were established by using the classical kinetics and grain size model.The results show that the dynamic recrystallization kinetic curves fitted under different deformation conditions are all"S"type.The increasing rate of dynamic recrystallization fraction is very low with low and high strain,while the increasing rate of dynamic recrystallization fraction increases obviously with medium strain.The recrystallized grain size increases with the increase of temperature and strain,and decreases with the increase of strain rate.According to the established dynamic recrystallization kinetics and dynamic recrystallization grain size model,it can not only provide parameter input for the simulation of microstructure evolution of superalloy during hot working process,but also provide theoretical basis for optimizing the process and then obtaining uniform microstructure.

关 键 词：GH4742高温合金 动态再结晶 动力学模型 晶粒尺寸模型 

分 类 号：TG153.1[金属学及工艺—热处理]