基于SA508Gr.4N钢微宏观唯象模型的核电管板锻件WHF法拔长工艺优化  

Process optimization of WHF stretching of nuclear tube sheet forging based on micro and macro phenomenological model of SA508Gr.4N steel

作　　者：李风雷[1] 曾志钦 汤传尧 张卫文[1] 何西扣[2] LI Feng-lei;ZENG Zhi-qin;TANG Chuan-yao;ZHANG Wei-wen;HE Xi-kou(School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou 510641,China;Institute for Specials Steels,Central Iron and Steel Research Institute,Beijing 100081,China)

机构地区：[1]华南理工大学机械与汽车工程学院,广东广州510641 [2]钢铁研究总院特殊钢研究所,北京100081

出　　处：《塑性工程学报》2021年第9期1-10,共10页Journal of Plasticity Engineering

基　　金：广东省自然科学基金资助项目(2015A030312003);国家自然科学基金资助项目(52074131);广东省国际科技合作项目(2021A0505030005)。

摘　　要：基于新一代核电材料SA508Gr.4N钢的动态热变形模拟数据及试样金相显微组织,借助Zener-Hollomon参数,采用线性回归分析,得到由应变速率及温度决定的SA508Gr.4N钢的动态再结晶晶粒演变微观模型,结合已建立的流动应力与应变、应变速率及温度的两段式宏观本构模型,基于DEFORM软件,进行二次开发,建立了SA508Gr.4N钢的有限元微宏观唯象模型。对标准动态热变形实验进行模拟,得到模拟值和实测值的相关系数为0.9524,验证了模型的有效性;设计非均匀变形试样并进行热压缩实验,6个典型点的晶粒尺寸平均误差约为16.78%,且试样不同位置晶粒尺寸的实验值和模拟值的变化趋势基本吻合,验证了模型在复杂热变形条件下的准确性。基于该模型对大型核电管板锻件首道次的宽砧强力压下锻造法拔长过程进行模拟,对比研究了在不同砧宽和布砧方式下锻件内部的等效应变、轴向应力和平均晶粒尺寸分布的差异,及其对锻件芯部质量的影响规律,发现采用2200 mm砧宽和水冒口交替布砧是最合理的工艺参数组合。Based on the dynamic thermal deformation simulation data and metallographic microstructure of new nuclear material SA508Gr.4N steel,using Zener-Hollomon parameter and linear regression analysis,the micro model of dynamic recrystallization grain evolution of SA508Gr.4N steel determined by strain rate and temperature was obtained.Combined with the established two-stage macro constitutive model between the flow stress and strain,strain rate and temperature,based on DEFORM software,the secondary development was carried out,and the micro and macro finit element phenomenological model of SA508Gr.4N steel was established.The standard dynamic thermal deformation experiments were simulated,and the correlation coefficient between the simulated values and measured values is 0.9524,which verifies the validity of model;the non-uniform deformation specimen was designed and thermal compression experiment was carried out,the average error of grain size of the six typical points is about 16.78%,and the change trend of experimental and simulated grain size in different areas of the specimen is quite consistent,which verifies the accuracy of model under complex thermal deformation conditions.Based on the model,the wide die heavy blow forging(WHF)stretching process of large-scale nuclear tube sheet forging in the first heating number was simulated,the distribution difference of equivalent strain,axial stress and average grain size with different anvil widths and anvil arrangement modes and the influence of different process parameters on the core quality of forging were compared and studied.It is found that the most reasonable process parameter combination is wide anvil of 2200 mm and alternately placing anvil on nozzle and riser.

关 键 词：SA508Gr.4N钢 WHF法拔长 数值模拟 砧宽 布砧方式 

分 类 号：TG316.2[金属学及工艺—金属压力加工]