采用相控阵超声横波探头对管径大于300 mm,壁厚大于30 mm的高铬合金钢管道对接焊缝实施周向检测,发现超标信号显示深度在一倍至两倍壁厚间时,检测仪器显示的缺陷位置深度和水平距离不能直接读取,难以直接依据标准来判废,而需通过换算才能确定缺陷的真实深度和水平距离。为此,分别利用公式计算法、画图法、模拟试块法、轴向扫查法和拍片法进行了缺陷信号的验证识别,获得了很好的效果,避免了误判,验证结果可为同类工件的周向相控阵超声检测信号识别提供参考。

Ultrasonic phased array shear wave probe was used to carry out circumferential inspection on butt weld of high chromium alloy steel pipe with pipe diameter more than 300 mm and wall thickness more than 30 mm. It is found that there is a signal exceeding the standard for one to two times of wall thickness and the defect location depth and horizontal distance displayed by the testing instrument cannot be read directly, so it is difficult to judge the rejection directly according to the standard. The true defect depth and horizontal distance can only be determined through conversion. In this paper, formula calculation method, drawing method, simulation test block method, axial scanning method and film method were used to verify and identify the defect signal, and good results were obtained, thus avoiding misjudgment. It can provide reference for the signal recognition of the same kind of workpiece by ultrasonic phased array detection.