摘要
选取传统高强度双相钢HC420/780DPD+Z和与其化学成分相同、组织存在一定量残余奥氏体差异的HC440/780DHD+Z为研究对象,研究了残余奥氏体对高强度双相钢断裂失效性能的影响。设计了5种表征不同断裂失效状态的试样,测试获得各试样的临界断裂应变和力-位移曲线;采用有限元法搭建了试样模型,并对比了试验和仿真关键参数误差,验证了模型的准确性。通过模型获取了各试样断裂单元的应力三轴度和临界断裂应变;基于MMC断裂失效模型拟合获得断裂失效曲线;采用90°V型弯曲试验和仿真对比分析验证了断裂失效曲线的准确性。结果表明,残余奥氏体组织加入后,高强度双相钢的抗拉强度基本保持不变,断后伸长率、强塑积和应变硬化指数明显提升;断裂失效性能明显提升,相同应力三轴度的极限断裂失效应变明显提高;90°V型弯曲模型获取的临界塑性应变与断裂失效曲线提取的数值一致,表明所获得的断裂失效曲线是可靠的;在基体组织中引入一定量的残余奥氏体组织有助于提升高强度双相钢碰撞过程中的承载吸能特性。
Taking traditional high-strength dual-phase steels HC420/780DPD+Z and HC440/780DHD+Z with the same chemical composition and a certain amount of residual austenite difference in structure as the research objects,the effects of retained austenite on fracture failure properties of high-strength dual-phase steel were studied.Five kinds of specimens characterizing different fracture failure states were designed,and the critical fracture strain and force-displacement curves of each specimen were obtained by test.The fimite element method was used to build the sample models,and the errors of key parameters were compared between test and simulation to verify the accuracy of the model.The stress triaxiality and critical fracture strain of each sample fracture element were obtained by the model.Based on MMC fracture failure model,the fracture failure curves were obtained by fitting.90°V-shaped bending test and simulation comparison analysis were used to verify the accuracy of the fracture failure curves.The results show that the tensile strength of high-strength dual-phase steel remains unchanged after the addition of retained austenite,the elongation after fracture,strength plastic product and strain hardening index increase significantly.The fracture failure properties are improved obviously,and the ultimate fracture failure strain of the same stress triaxiality is obviously improved.The critical plastic strain obtained by the 90°V-shaped bending model is consistent with the value obtained from the fracture failure curves,which indicates that the obtained fracture failure curve is reliable.The introduction of a certain amount of retained austenite in matrix structure is helpful to improve the bearing energy absorption characteristic of high-strength dual-phase steel during collision.
作者
张伟
刘华赛
桑贺
李春光
陈洪生
宋起峰
ZHANG Wei;LIU Hua-sai;SANG He;LI Chun-guang;CHEN Hong-sheng;SONG Qi-feng(Research Institute of Technology,Shougang Group Co.,Ltd.,Beijing 100043,China;QC Department,Shougang Jingtang United Iron and Steel Co.,Ltd.,Tangshan 063210,China;General Research and Development Institute,China FAW Co.,Ltd.,Changchun 130000,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2023年第11期185-193,共9页
Journal of Plasticity Engineering
基金
河北省重点研发计划项目(20311004D)。
关键词
残余奥氏体
高强度双相钢
断裂失效
应力状态
模型
retained austenite
high-strength dual-phase steel
fracture failure
stress state
model
