钢制对接焊缝内部缺陷类型的超声TOFD-D扫描图像表征

本研究针对对接焊缝常见缺陷的超声TOFD-D扫描图像，通过对比分析获得可用于识别缺陷类型的图像特征；结合检测信号特征，识别焊缝常见缺陷的类型。研究结果表明:超声TOFD-D扫描图像与缺陷几何形状密切相关，可用于表征缺陷类型；焊缝常见缺陷如侧壁未熔合、根部未焊透、气孔、裂纹的D扫描图像特征体现在条纹现状、抛物线开口方向及端部曲率，基于这些图像特征可识别缺陷类型；此外，将超声TOFD-D扫描图像特征与超声TOFD检测信号特征相结合可进一步提高对缺陷类型的识别能力。

Ultrasonic TOFD-D Scanning Image Characterization on the Type of Inner Defect of Steel Butt Welds

In the research, the method of charactering the type of weld defects is proposed, and image features which can be used to identify the type of defects can be obtained through comparing and analyzing on the imagery from different samples. Moreover, the characteristics of testing signal are analyzed to help identify defect types. The result indicates that the ultrasonic TOFD-D scan image is closely related to the geometry of the defect, and the extracted image features can be used to characterize the geometric shape of the defect, and then characterizing the defect's type. Combining with ultrasonic test signal, the types of common defects, such as crack, lack of penetration, incomplete fusion, slag inclusion, and porosity can be effectively identify through TOFD D scan imagery of defects.