摘要
借助高性能红外热像仪对SUS301L-Q235B异种材料点焊接头的SUS301L不锈钢侧熔核及塑性环表面局部热点进行监测,建立了异种材料点焊接头温升斜率与疲劳极限间的定量关系,提出了一种基于温升斜率转折点预测异种材料点焊接头疲劳极限的方法.结果表明,SUS301L-Q235B异种材料点焊接头向Q235B侧发生了较严重的熔核偏移,导致不锈钢侧承载能力降低;点焊接头在高频循环剪切拉伸作用下,SUS301L不锈钢侧熔核及塑性环表面热点表现出“4个阶段”的温度演化特征;利用红外热像法预测的疲劳极限为5.569 kN,采用传统阶梯法试验获得的疲劳极限为5.875 kN,预测值与试验值之间的误差为5.21%,具有较高的一致性.所提出的疲劳极限快速预测方法能够克服传统疲劳试验方法的局限性,实现异种材料点焊接头疲劳极限的非接触、非破坏快速预测,具有重要的工程意义和科研价值.
In this paper,with the help of high performance infrared thermal imager,local hot spots of nugget and plastic ring on the side of SUS301L stainless steel of the SUS301L-Q235B dissimilar materials spot-welded joint was monitored.And the quantitative relationship between the temperature rise slope and the fatigue limit of the welding joint of dissimilar materials was established.Then,a method to predict the fatigue limit of the spot-welded joint of dissimilar materials based on the tipping point of temperature rise.The results show that a serious nugget migration generates on the Q235B side of SUS301L-Q235B dissimilar materials spotwelded joint,which results in reduction of the carrying capacity of stainless steel.Under the action of high frequency shear tensile,the"four stages"temperature evolution characteristics are presented.The fatigue limit predicted by infrared thermography was 5.569 kN.The fatigue limit obtained by the traditional staircase method was 5.875 kN.The error between the predicted value and the test value was 5.21%,which presents a high concordance.The rapid fatigue limit prediction proposed in this paper can overcome the limitations of the traditional fatigue test method and realize non-contact and nondestructive prediction of spot-welded joint fatigue limit of dissimilar materials,which has important engineering significance and research value.
作者
孙杨
刘亚良
李赫
杨鑫华
许鸿吉
SUN Yang;LIU Yaliang;LI He;YANG Xinhua;XU Hongji(Dalian Jiaotong University,Dalian,116028,China;Liaoning Key Laboratory of Welding and Reliability of Rail Transportation Equipment,Dalian,116028,China)
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2020年第1期61-66,I0004,共7页
Transactions of The China Welding Institution
基金
国家自然科学基金资助项目(51875072)
辽宁省自然科学基金(No.2015020169)。
关键词
红外热像法
异种材料
条件疲劳强度
快速评定
点焊
infrared thermography
dissimilar materials
fatigue strength
rapid assessment
spot welding
作者简介
第一作者:孙杨,1993年出生,硕士,主要从事焊接结构疲劳可靠性等方向的研究,Email:sunyangdl@126.com;通信作者:杨鑫华,1969年出生,博士,教授,Email:yangxh@djtu.edu.cn.
