基于双正交法的焊缝早期隐性损伤临界状态磁记忆特征  

Metal Magnetic Memory Critical Characteristics of Early Hidden Damage of Welded Joints Based on the Biorthogonal Method

作　　者：邢海燕[1] 王犇 王学增[1] 刘长海[1] 党永斌 

机构地区：[1]东北石油大学机械科学与工程学院大庆163318

出　　处：《机械工程学报》2015年第16期71-76,共6页Journal of Mechanical Engineering

基　　金：国家自然科学基金(11272084,11072056);黑龙江省博士后科研启动基金(LBH-Q13035);黑龙江省应用技术研究与开发计划(GA13A402)资助项目

摘　　要：针对焊缝早期隐性损伤临界状态磁记忆特征提取及评价难题,在大量试验基础上提出双正交法:即焊缝检测路径的正交性和磁场矢量分析的正交性。以Q235B焊接试件为试验材料,通过测量焊缝纵向和横向磁记忆信号分布,引入磁场正交矢量空间图和李萨如图,研究疲劳载荷下焊缝隐性损伤演化的磁记忆表征规律,对比扫描电镜和X射线检测结果,获得焊缝早期隐性损伤临界状态磁记忆特征:隐性损伤出现时李萨如图会产生涡动性的局部闭合,随着损伤的扩展涡动性局部闭合的面积越来越大直至断裂时完全闭合。在此基础上提出正交矢量梯度积分S(K)和正交矢量合成梯度比Kr的概念,建立Kr与剩余寿命Nr定量关系模型,为焊缝早期隐性损伤临界状态的定量研究提供一种新的思路。According to the bottleneck of metal magnetic memory （MMM） critical characteristic extracting for early hidden damage of welded joints, the biorthogonal method is presented, that is, the orthogonal testing path and the MMM orthogonal vector analysis based on experiments. The experimental materials are Q235B welded plate specimens. By measuring the normal component and the tangential component signals, the magnetic field vector space figure and the Lissajous figure are introduced. By contrasting the results of scanning electron microscope and X ray detection, the MMM changing laws and the critical characteristics of early hidden damage are obtained. The Lissajous figure becomes partial closure when the early hidden damage occurs. And the partial closure area becomes larger and larger with the expansion of the hidden damage. Furthermore, the Lissajous figure becomes completely closed till the specimen is broken. At last two new MMM parameters are presented, that is, the integral of orthogonal gradient vector （S（K）） and the ratio of orthogonal gradient vector sum （Kr）. And the quantitative relational model between Kr and the residual life ratio Nr is built which provides a new quantitative evaluation tool of early hidden damage for welded joints in practical engineering.

关 键 词：双正交 隐性损伤 磁记忆 焊缝 

分 类 号：TG156[金属学及工艺—热处理]