25MnB热成形钢的动态再结晶行为及组织演变  

Dynamic recrystallization behavior and microstructure evolution of 25MnB hot forming steel

作　　者：付艺枫 陈兴召 兰亮云 常智渊 程旭 崔丽[4] Fu Yifeng;Chen Xingzhao;Lan Liangyun;Chang Zhiyuan;Cheng Xu;Cui Li(School of Mechanical Engineering and Automation,Northeastern University,Shenyang 110819,China;Pangang Group Research Institute Co.,Ltd.,Panzhihua 617000,China;The first Military Representative Office in Shenyang,Shenyang 110039,China;Shenyang Aircraft Corporation Co.,Ltd.,Shenyang 110039,China)

机构地区：[1]东北大学机械工程与自动化学院,辽宁沈阳110819 [2]攀钢集团研究院有限公司,四川攀枝花617000 [3]空装驻沈阳地区第一军事代表室,辽宁沈阳110039 [4]沈阳飞机工业集团有限公司,辽宁沈阳110039

出　　处：《锻压技术》2024年第12期198-207,共10页Forging & Stamping Technology

摘　　要：基于热压缩实验研究了25MnB钢在变形温度为850~1150℃、应变速率为0.01~30 s^(-1)范围内的动态再结晶行为(DRX)。利用加工硬化率理论求解其DRX临界应变,并建立了临界应变模型,基于Avrami模型描述了DRX动力学和晶粒尺寸演变规律,并将模型嵌入到DEFORM-3D有限元软件中,实现了对25MnB钢DRX行为的可视化模拟。结果表明,25MnB钢试样的等效应变和等效应变速率演变均显示出不均匀性,DRX程度与等效应变分布具有依赖性。变形条件对DRX体积分数和晶粒尺寸演变影响显著,随着温度的降低和应变速率的增加,中心区域发生完全DRX,晶粒尺寸得到明显细化;但由于局部不充分DRX现象,同一截面上晶粒尺寸分布的不均匀性也随之增加。DEFORM有限元仿真结果与实验结果具有较好的一致性,为预测25MnB钢在热冲压过程的组织演变提供依据。Based on hot compression experiment,the dynamic recrystallization(DRX)behavior of 25MnB steel at the deformation temperatures of 850-1150℃and the strain rates of 0.01-30 s^(-1) was studied.Then,the critical strain of its DRX was solved by the theory of work hardening rate,and the critical strain model was established.Furthermore,based on Avrami model,the DRX dynamics and grain size evolution laws were described,and these models were embedded into finite element model software DEFORM-3D to achieve visual simulation of DRX behavior for 25MnB steel.The simulation results indicates that the evolution of equivalent strain and equivalent strain rate for 25MnB steel samples exhibits non-uniformity,and the degree of DRX is dependent on the distribution of equivalent strain.The deformation conditions have a significant impact on the evolution of DRX volume fraction and grain size.With the decreasing of temperature and the increasing of strain rate,the complete DRX occurs in the central region,and the grain size is significantly refined.However,due to the insufficient local DRX phenomenon,the non-uniformity of grain size distribution on the same cross-section is also increased.The finite element simulation results of DEFORM are in good agreement with the experimental results,providing a basis for the microstructural evolution prediction of 25MnB steel during the hot stamping process.

关 键 词：25MnB钢 热压缩 动态再结晶 动力学模型 应变不均匀性 组织演变 

分 类 号：TG307[金属学及工艺—金属压力加工]