摘要
为了揭示先进高强钢板在冲压成形后回弹随时间而改变的时效回弹行为,对DP780和TRIP780钢板进行了U形件冲压和圆筒件剖环试验。对U形件角度和剖环开口位移在卸载后10 s至84 d内的回弹量进行了跟踪测量,通过拟合试验数据建立了计算时效回弹量的经验模型。结果表明,DP780和TRIP780钢板冲压卸载后均有显著的时效回弹行为,总时效回弹量约为初始回弹量的3%~5%,回弹量随时效时间先快速增加而后趋于稳定。在材料不同、几何形状相同的情况下,冲压件的时效回弹速率不同。在U形件冲压中,DP780钢板在卸载后3天的总时效回弹量约为50%,而TRIP780钢板在卸载后6 h内就产生了相同的时效回弹量。同一材料圆筒件剖环开口处的时效回弹量大于U形件的时效回弹量。两种材料的时效回弹量均可用指数函数来表达,该式可为时效回弹的预测提供参考。
To reveal the time-dependent springback behavior that sprinback changing with time of advanced high strength steel sheet after stamping forming,stamping tests of U-shaped parts and ring splitting tests of cup parts were performed for DP780 and TRIP780 steel sheets. The springback amount of U-shaped parts angle and split ring opening displacement were monitored during the period of 10 s to 84 d after unloading. An empirical model for calculating the time-dependent springback amount was established by fitting the test data.The results show that both DP780 and TRIP780 steel sheets show prominent time-dependent springback behavior after unloading,and the total time-dependent springback amount is about 3%-5% of the initial springback amount. The springback amount increases rapidly at first and then tends to stabilize with time. In the case of different materials and the same geometric shape,the time-dependent springback velocities of stamping parts are different. In stamping of U-shaped parts,the total time-dependent springback amount in 3 days after unloading for DP780 steel sheet is about 50%,while the same springback amount occurs within 6 h after unloading for TRIP780 steel sheet.The time-dependent springback amount at the split ring opening of cup parts with the same material is greater than that of U-shaped parts.The time-dependent springback amount of both the two materials can be expressed by an exponent function,which can provide reference for the prediction of time-dependent springback.
作者
余海燕
吴航宇
汪林
YU Hai-yan;WU Hang-yu;WANG Lin(School of Automotive Studies,Tongji University,Shanghai 201804,China;SAIC Maxus Automotive Co.,Ltd.,Shanghai 200438,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2021年第6期2-7,共6页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(51175382)
上海市自然科学基金资助项目(19ZR1460100)。
关键词
时效回弹
高强钢板
U形件
圆筒件剖环
冲压成形
time-dependent springback
high strength steel sheet
U-shaped parts
ring splitting of cup parts
stamping forming
