摘要
目的针对目前车用高强钢和高强度铝合金板料在无铆连接工艺上出现的成形接头效果不佳及接头强度难以满足实际工况等问题,提出一种钢/铝异种材料热无铆塑性连接工艺,以有效提高22MnB5高强钢与7050铝合金铆接接头性能。方法通过软件Abaqus建立钢/铝异种材料无铆塑性连接有限元模型,对塑性连接接头尺寸特性进行分析;进一步通过仿真分析研究高强钢初始铆接温度对接头截面颈厚与自锁值的影响,并采用拉伸试验研究铝板在不同初始温度下及成形接头在不同冷却方式下对无铆塑性连接接头性能的影响。结果将有限元仿真分析结果与试验的金相图进行了对比研究,得出二者成形接头的尺寸基本吻合,并产生了有效的机械自锁,证明了仿真模型的准确性。随后,经仿真分析确定,钢加热至700℃时,接头颈厚值与自锁值均最大,分别为0.402、0.357 mm,该成形温度下接头特征尺寸最佳。最后,通过试验分析发现,常温铆接、阀冷、室冷、水冷的拉力峰值分别为2.0763、5.3140、2.4111、2.0240 kN。由此可得,热处理后接头的抗剪切强度较常温铆接提高了28.5%,在3种冷却方式处理下,阀冷的接头强度最佳,水冷的接头强度最差。结论通过对比分析,确定了22MnB5钢加热至700℃且铝仅经热传导并采用阀冷时进行无铆塑性连接的接头强度最佳。
The work aims to propose a hot clinching plastic connection process for steel/aluminum dissimilar materials to improve the connection performance of riveted joint between 22MnB5 high-strength steel and 7050 aluminum alloy,thus solving the problems that the joint forming effect of high-strength steel and high-strength aluminum alloy sheet for automobile in the clinching connection process is not good and the joint strength is difficult to meet the actual working conditions.A finite element model of the clinching plastic connection of steel/aluminum dissimilar materials was established by the software Abaqus,and the characteristic size of the plastic joint was analyzed.Further,the effects of initial high-strength steel clinching temperature on the sectional neck thickness and the self-locking value of the joint were studied by simulation analysis,and tensile tests were also used to study the effects of aluminum sheets at different initial temperature and formed joints under different cooling methods on the performance of clinching plastic joints.A comparative study was carried out between the finite element simulation analysis and the experimental metallography,showing that the sizes of the two formed joints were basically matched and an effective mechanical self-locking was produced and proving the accuracy of the simulation model.Subsequently,the simulation analysis determined that the joint neck thickness and self-locking value reached the maximum value of 0.402 mm and 0.357 mm respectively at 700℃and the joint had the best characteristic size at this forming temperature.In the final test,the peak tensile of clinching joint at room temperature was 2.0763 kN,the peak tensile of the valve-cooled joint was 5.3140 kN,the peak tensile of the joint cooled at room temperature was 2.4111 kN and the peak tensile of the water-cooled joint was 2.0240 kN.Thus,compared to clinching joints at room temperature,the shear strength of joints after heat treatment increased by 28.5%,and the valve-cooled joints had the best strength and the water-cooled joints had the worst strength under the three cooling methods.Through comparative analysis,it is determined that the joint of 22MnB5 steel heated to 700℃with aluminum only by heat conduction has the best strength for clinching plastic joint under valve cooling.
作者
谷东伟
陈光
李奇涵
高嵩
GU Dong-wei;CHEN Guang;LI Qi-han;GAO Song(School of Mechanical Engineering,Changchun University of Technology,Changchun 130012,China)
出处
《精密成形工程》
北大核心
2023年第4期49-57,共9页
Journal of Netshape Forming Engineering
基金
吉林省科技发展计划(20190302100GX,20200401115GX)。
关键词
钢/铝
异种材料
热无铆塑性连接
接头性能
拉伸试验
steel/aluminum
dissimilar materials
hot clinching plastic connection
joint performance
tensile test
