摘要
为研究超声振动对低碳钢热变形中奥氏体再结晶过程的影响,基于Gleeble-1500热模拟试验和对变形后淬火试样原始奥氏体晶界观测,构建Q235钢热压缩变形抗力和奥氏体平均晶粒尺寸数学模型,对超声振动和常规压缩变形条件下低碳钢圆柱试样的热压缩过程进行仿真分析。结果表明,超声振动导致试样一端变形如倒置的伞状,发生奥氏体动态再结晶所需临界变形程度明显降低;奥氏体动态再结晶首先从试样超振激励端开始,变形后试样内最小奥氏体晶粒尺寸约为20μm;超声振动变形试验表明,试样表层组织纳米化,内部晶粒尺寸相比常规压缩明显细化。
In order to study the effect of ultrasonic vibration on the recrystallization of austenite in hot deformation of low carbon steel, constitutive equations of Q235 steel undertaken high temperature hot compression deformation were developed based on the results of experiments carried out on the Gleeble-1500, and the austenite grain size evolution mod- els parameters were determined based on the metallographic observation of the original austenite grain boundary. FEM simulations of specimen compressed with and without ultrasonic vibration excitation were performed utilizing the VU- MAT subroutine presented in Abaqus/Explicit solver to simulate deformed shape of the specimen and the average austen- ite grain evolution process. It was shown that the end of specimen excited by ultrasonic vibration toolset formed as an in- verted umbrella shape, and the threshold deformation of austenite dynamic recrystallization was significantly decreased. Dynamic recrystallization of austenite occurs first at the end of the specimen contacted with the ultrasonic vibration toolset, and the minimum austenite grain size after deformation is about 20 μm. Experimental results show that the surface microstructure is nanocrystallized and the internal grain is much finer than that of the conventional compression.
作者
贺庆强
朱寒
耿春丽
柴万里
刘建国
HE Qing-qiang;ZHU Han;GENG Chun-li;CHAI Wan-li;LIU Jian-guo(College of Mechanical and Electronic Engineering,China University of Petroleum,Qingdao 266580,Shandong,China)
出处
《钢铁》
CAS
CSCD
北大核心
2018年第10期61-66,共6页
Iron and Steel
基金
山东省重点研发计划资助项目(2017GGX30129)
中央高校基本科研业务费专项资金资助项目(18CX02090A)
关键词
超声振动
Q235钢
动态再结晶
有限元分析
ultrasonic vibration
Q235 steel
dynamic recrystallization
finite element analysis
