高强钢点焊熔合界面正向拉伸撕裂失效评价分析  

Failure Analysis of Fracture of High Strength Steel Spot-welded Joints about Cross Tension Testing

作　　者：金泉军 高明 吕玲芳 曾泳 JIN Quanjun;GAO Ming;LV Lingfang;ZENG Yong(Zhejiang Geely New Energy Commercial Vehicle Groud Co.,Ltd.,Hangzhou 311228,China)

机构地区：[1]浙江吉利远程新能源商用车集团有限公司,浙江杭州311228

出　　处：《电焊机》2023年第1期31-37,共7页Electric Welding Machine

摘　　要：基于界面撕裂和熔核剥离两种模式下焊点的不同应力分布规律,通过应用极限应力理论及Mises应力,计算两种失效模式下高强度钢焊点的最大载荷,推导出界面撕裂失效时的临界熔核直径d_(cr1)=(3/3)(2n+2)t(1-I%)H_(max)^(HAZ)/H_(max)^(nugget)。通过正交试验方法对高强钢焊点正向失效模式进行分析验证,结果发现,当实测熔核直径小于临界熔核直径时,焊点发生明显的界面撕裂模式;当实测熔核直径大于临界熔核直径时,发生明显的熔核剥离模式;焊接电流对高强度钢的焊点熔核直径影响最大,对焊点失效方式有较大影响。According to the different stress distribution under interfacial fracture mode and button pull-out mode,the maximum force on high strength steel spot-welded joints for two kinds of failure modes were analysised and calculated based on Mises criteria and ultimate stress theory.The critical weld diameter d_(cr1)=(3/3)(2n+2)t(1-I%)H_(max)^(HAZ)/H_(max)^(nugget) for interfacial tearing failure was calculated.High strength steel was used to validate the critical weld diameter by the orthogonal test.The results showed that when the measured nugget diameter was smaller than the critical nugget diameter,interfacial fracture mode appeared in the welding nugget;when the measured nugget diameter was larger than the critical nugget diameter,button pull-out mode appeared.At the same time,the welding current had the greatest effect on the nugget diameter to resistance spot welding of high strength steel,and it had a great effect on the fracture mode of sold-welded joints.

关 键 词：高强度钢 界面撕裂 熔核剥离 正向拉伸 失效分析 熔核直径 

分 类 号：TG457.11[金属学及工艺—焊接]