基于 SAM 的不锈钢点焊接头无损检测

运用超声波扫描显微镜(SAM)对1 mm厚SUS304不锈钢薄板点焊接头进行无损检测,分析不同焊接工艺条件下的C扫描图像,并对C扫描图像各特征区域的A扫描信号进行采集、分析,研究两者间的对应关系,通过超声波C扫描成像法对焊核直径进行测量。结果表明:超声波扫描显微镜可以检测不锈钢点焊接头缺陷,并通过C扫描图像区分缺陷类型;在电极压力为0.15 MPa、焊接电流大于8 k A时,C扫描图像可以清楚的反映飞溅、过烧等缺陷;C扫描图像各特征区域表现出不同的A扫描信号特征;基于超声波C扫描测量的焊核直径为4.39~5.25 mm。

Nondestructive Testing of Spot Welded Joints of Stainless Steel Based onScanning Acoustic Microscope

Non-destructive testing of spot weld joints on 1 mm thick SUS304 stainless steel sheet is carried out

by the scanning acoustic microscope(SAM). The C-scan images under different welding process are analyzed, and A-

scan signals in the specific parts of the C-scan images are collected and processed. Then the relationship between

them is analyzed. The diameter of the spot weld is measured through ultrasonic C-scan imagery method. The result

show that SAM can be used to inspect the flaws of spot welded joints. The C-scan images can be used to distinguish

the type of inner defects. When the electrode force is 0. 15 MPa and the welding current is 8 kA or above C-scan ima-

ges can clearly reflect the splash and burnt and so on. The A-scan signals of the specific parts of the ultrasonic C-scan

images are different. The diameter of the spot weld are in the range of 4. 39 to 5. 25 mm based on ultrasonic C-scan

imagery method.