电阻点焊超声在线监测  

Ultrasonic Online Monitoring of Resistance Spot Welding

作　　者：刘春秘 张佳莹 陈一淳 赵新玉[2] 曹浩 LIU Chunmi;ZHANG Jiaying;CHEN Yichun;ZHAO Xinyu;CAO Hao(Shenyang Aircraft Industry Group of China,Shenyang 110890,China;School of Material Science and Engineering,Dalian Jiaotong University,Dalian 116028,China;Harbin Welding Institute Limited Company,Harbin 150028,China)

机构地区：[1]沈阳飞机工业(集团)有限公司,辽宁沈阳110890 [2]大连交通大学材料科学与工程学院,辽宁大连116028 [3]中国机械总院集团哈尔滨焊接研究所有限公司,黑龙江哈尔滨150028

出　　处：《电焊机》2023年第8期138-143,共6页Electric Welding Machine

基　　金：国家自然科学基金项目(51905070);辽宁省教育厅2021年度科学研究经费项目(LJKZ0492)。

摘　　要：电阻点焊质量决定了车身强度和车辆安全。超声无损检测方法常用于焊后抽检,但车身焊装完成后,结构内部诸多焊点难以触及,无法检测。针对上述问题,将超声检测技术应用于焊接过程监测,基于脉冲-回波超声探头与特征信号分析技术,研究点焊过程工件内部超声场瞬态分布情况;设计了新型内置超声波探头电极结构,将超声探头嵌入电极动臂水冷腔,进行脉冲电阻点焊超声在线监测试验,分析超声时程、焊接过程超声回波特征;利用声学信号实时记录焊核熔化和凝固过程,并研究点焊典型焊接缺陷虚焊的超声回波图特征,分析基于回波的虚焊焊点鉴别方法。研究结果表明,通过观察C扫描图像特征与A扫描信号的变化,能够很好地划分点焊接头的热影响区、熔合区、熔核区以及焊接缺陷。通过C扫描图像特征对虚焊焊点进行快速识别,进而实现点焊缺陷检测和熔核尺寸测量。The quality of spot welding determines the strength and safety of the vehicle body.Ultrasonic non-destructive testing methods are commonly used for spot inspection after welding.But many welding points of the structure are difficult to reach and cannot be detected when the welding is completed.In order to address the problem,ultrasonic testing technology is applied to the monitoring of welding process.Based on pulse-echo ultrasonic probe and characteristic signal analysis technology,the transient distribution of ultrasonic field inside the workpiece during spot welding process is studied.A new type of built-in ultrasonic probe electrode structure is designed.The ultrasonic probe is embedded in the water-cooled cavity of the electrode boom,and the ultrasonic on-line monitoring test of pulse resistance spot welding is carried out.The characteristics of ultrasonic time history and ultrasonic echo diagram during welding process are analyzed.The melting and solidification process of the nugget is recorded in real time by using acoustic signals,and the characteristics of the ultrasonic echo diagram of the virtual welding of the typical spot welding defects are studied,and the identification method of the virtual welding spot based on the echo diagram is analyzed.The results show that the heat affected zone,fusion zone,nugget zone and welding defects of spot welded joints can be well divided by observing the characteristics of C-scan images and A-scan signals.The virtual welding spot can be quickly identified by the characteristics of the display diagram,and then the spot welding defect detection and nugget size measurement can be realized.

关 键 词：超声无损检测 电阻点焊 焊核熔化 过程监测 

分 类 号：TB553[理学—物理]