摘要
以304不锈钢为研究对象,采用有限元法对实验钢管热挤压过程中的微观组织演变展开研究。首先,使用热模拟机进行了单道次热压缩实验,确定了实验钢的本构方程和动态再结晶模型。然后,在ABAQUS软件上建立热压缩和热挤压过程的热力耦合模型后,通过热压缩模拟与实验对比,验证了该数值模型的准确性。最后,对实验钢的热挤压模拟温度场和应力、应变场的变化规律进行了深入分析,同时借助ABAQUS的二次开发功能,对微观组织演变进行了数值模拟,揭示了动态再结晶体积分数、晶粒尺寸、平均晶粒尺寸以及晶粒分布均匀性等的变化规律。结果表明:在挤压前期,钢管前端的晶粒尺寸粗大,而在稳态阶段和挤压后期,钢管晶粒尺寸较小且分布均匀;随着坯料初始温度的升高和挤压速度的增加,晶粒尺寸分布均匀性均呈先增加后降低的趋势。
For 304 stainless steel,the microstructural evolution of experimental steel tube during the hot extrusion process was studied by using the finite element method.Firstly,a single-pass hot compression experiment was performed by using a thermal simulator,and the constitutive equation and dynamic recrystallization model of the experimental steel were determined.Then,after establishing a thermo-mechanical coupling model for the hot compression and hot extrusion processes in software ABAQUS,the accuracy of the numerical model was verified by comparison between the simulation and experiment of hot compression.Finally,the change laws of the temperature and stress-strain fields during the hot extrusion simulation of the experimental steel were further analyzed,and the microstructural evolution were numerically simulated with the help of the secondary development function of ABAQUS to reveal the change laws in dynamic recrystallization volume fraction,grain size,average grain size and grain distribution uniformity.The results show that in the early stage of extrusion,the grain size at the front end of steel tube is coarse,while in the steady-state and later stages of extrusion,the grain size of steel tube is smaller and evenly distributed.With the increasing of initial billet temperature and extrusion speed,the uniformity of grain size distribution both show a trend of first increase and then decrease.
作者
李春雨
邱春林
Li Chunyu;Qiu Chunlin(State Key Laboratory of Rolling Technology and Continuous Rolling Automation,Northeastern University,Shenyang 110000,China)
出处
《锻压技术》
CAS
CSCD
北大核心
2024年第10期56-64,74,共10页
Forging & Stamping Technology
基金
国家重点研发计划(2021YFB3702001)。
关键词
304不锈钢
动态再结晶
热挤压
微观组织演变
晶粒尺寸
304 stainless steel
dynamic recrystallization
hot extrusion
microstructure evolution
grain size
