基于超声TOFD法B扫描图像预测的缺陷定位  

Defect localization based on ultrasonic TOFD B-scan image prediction

作　　者：迟大钊[1] 王梓明 刘海春 李庆生 郭强 苏维刚 贾涛 CHI Dazhao;WANG Ziming;LIU Haichun;LI Qingsheng;GUO Qiang;SU Weigang;JIA Tao(State Key Laboratory of Precision Welding&Joining of Materials and Structures,Harbin Institute of Technology,Harbin,150001,China;China National Petroleum Pipeline Engineering Group Quality Supervision and Inspection Co,Beijing,100013,China)

机构地区：[1]哈尔滨工业大学,材料结构精密焊接与连接全国重点实验室,哈尔滨150001 [2]国家管网集团工程质量监督检验有限公司,北京100013

出　　处：《焊接学报》2024年第12期1-6,共6页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(52375328)。

摘　　要：在超声衍射时差法(time of flight diffraction, TOFD)B扫描图像中,缺陷端部衍射波影像呈类抛物线形态,类抛物线的顶点在图像中的位置代表了缺陷端部在焊缝横截面中的位置.当被检测焊缝存在焊缝余高时,跨越焊缝的B扫描无法实施,因此不能对缺陷进行准确定位,针对这一问题,提出一种基于超声TOFD法B扫描图像预测的缺陷端部定位方法,根据B扫描路径上超声探头与缺陷端部的动态位置关系,建立缺陷类抛物线影像的预测模型;通过采集B扫描路径上的两列A信号,利用模型,对缺陷端部类抛物线顶点坐标进行计算,并获得缺陷端部在焊缝横截面中的位置信息.利用文中所提方法,对人工缺陷及焊接缺陷进行定位测量.结果表明,所提方法利用两列A信号,可以有效克服焊缝余高限定检测可达性所带来的技术弊端,并获取缺陷端部在焊缝截面中的位置信息.In the B-scan image of the ultrasonic TOFD method,the diffraction wave image of defects appears in a parabola-like shape.In the coordinate system of the weld cross-section,the coordinates of the vertex of the parabola-like shape represent the position of the defect tip.When the inspected weld has a large reinforcement,the B-scan cannot be performed,thus failing to accurately locate the defect.To address this issue,a prediction model for the parabola-like image of defects is established based on the dynamic positional relationship between the ultrasonic probe and the defect end along the B-scan path.By collecting two A-signals from the B-scan inspection,the model is used to calculate the coordinates of the vertex of the parabola-like image of defects,thereby obtaining the position information of the defects.This forms a method for defect tip positioning based on the prediction of B-scan images in the ultrasonic TOFD method.The results of artificial and welding defect detection show that the proposed model and method can obtain the position information of defects in the weld cross-section using two A-signals,effectively overcoming the technical drawbacks caused by the limited accessibility of detection due to weld reinforcement.Highlights:(1)Based on the dynamic position changes between the ultrasonic probe and the defect ends during the B-scan process of the ultrasonic TOFD method,we establish a mathematical model to realize the prediction of the shape of defect tip diffraction wave in B-scan images.(2)In order to solve the problem of B-scan implementation difficulties in TOFD due to weld reinforcement,the location of defect tips within the weld cross-section is calculated using two ultrasonic TOFD A-signals,enabling non-scanning-based defect localization.

关 键 词：超声TOFD法 B扫描图像 焊缝余高 缺陷定位 

分 类 号：TG409[金属学及工艺—焊接]