高强钢-铸铝自冲铆接头成形关键影响因素分析  

Analysis on key factors influencing the forming of high-strength steel-cast aluminum self-piercing riveting joints

作　　者：屈莹莹 周长学 符平坡 高文杰 Qu Yingying;Zhou Changxue;Fu Pingpo;Gao Wenjie(Body Trial Production Department,Geely Automobile Research Institute(Ningbo)Co.,Ltd.,Ningbo 315336,China;Ningbo Geely Automotive Research&Development Co.,Ltd.,Ningbo 315336,China;School of Mechanical Science&Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]吉利汽车研究院(宁波)有限公司车身试制部,浙江宁波315336 [2]宁波吉利汽车研究开发有限公司,浙江宁波315336 [3]华中科技大学机械科学与工程学院,湖北武汉430074

出　　处：《锻压技术》2025年第2期167-177,194,共12页Forging & Stamping Technology

摘　　要：对于高强钢及铸铝的自冲铆接,结合试验及数值分析研究了影响接头成形的关键因素及机理。结果表明:铆钉过短则难以刺入下板,但过长则易发生钉腿溃缩,实际使用中钉长超过板材总厚度0.5~1.5 mm为宜。适度提高铆钉硬度,可延缓和缩短钉腿镦粗的时间,从而有效改善铆钉镦粗状况,但铆钉硬度过大会降低互锁值,不利于形成良好的接头。增大上板强度及厚度则钉脚受力范围扩大,钉腿更易向外扩张,但钉腿所受等效应力超过铆钉抗拉强度,会加剧钉腿镦粗,影响接头成形。铸铝下板延展性相对不足,容易产生接头开裂,且开裂多发生在应力三轴度为正的接头凸起底部边缘,随着铆模深度增大,凸起底部边缘应变值也增加,更容易发生开裂,因此,铆模深度应控制在0.9~1.0 mm。For the self-piercing riveting of high-strength steel and cast aluminum,combining experiment and numerical analysis,the key factors and mechanisms affecting the joint forming were studied.The results show that it is difficult to penetrate the lower plate when the rivet is too short,but using the excessively long rivet can easily cause the rivet legs to collapse.In the actual using,the length of rivet should exceed the total thickness of plate by 0.5-1.5 mm.Moderately increasing the rivet hardness can delay and shorten the time for rivet leg upsetting to improve the condition of rivet upsetting effectively.However,when the hardness of rivets is too high,it reduces the interlock value,which is not conducive to form a good joint.Increasing the strength and thickness of upper plate expands the range of force on the rivet feet,resulting in the rivet legs to expand outward.However,when the equivalent stress of rivet legs exceeds the tensile strength of rivet,it exacerbates the upsetting of rivet legs and affects the forming of joint.The ductility of cast aluminum lower plate is relatively insufficient,which is prone to joint cracking,and the cracking often occurs at the bottom edge of the joint protrusion with positive stress triaxiality.With the increasing of riveting die depth,the strain value of the protrusion bottom edge also increases,making it more prone to cracking.Therefore,the riveting die depth should be controlled within 0.9-1.0 mm.

关 键 词：自冲铆接 高强钢 铸铝 互锁值 铆模深度 

分 类 号：TG938[金属学及工艺—钳工工艺]