裂纹在管道制造和运行中比较常见, 危害性很大。为了提这类缺陷的检测精度, 采用超声回波幅度法和ADDT技术(振幅-距离差技术)对管道裂纹进行了试验研究。试验得出, 回波幅度法适用于测量深度<1.5 mm裂纹的尺寸; 对深度>1.5 mm的裂纹型缺陷, 推荐使用ADDT技术进行定量。随着裂纹径向深度的增加, 两种方法的测量误差均有所增大, 但回波幅度法的误差增加更多。试验得出, 定量检测精度的影响因素较多, 有超声仪器、检测人员自身水平, 裂纹的方向、形状等, 因此, 检测时应综合考虑相关因素。

Crack is a general defect in the manufacture and operation of the pipeline, and it is harm to the pipeline. In order to raise the inspection accuracy of this type of defect, ultrasonic testing method was used with two methods such as echo amplitude and ADDT method to evaluate the crack quantitatively. The experiments showed that the echo amplitude method was suitable to evaluate the crack with depth less than 1.5 mm, and the ADDT method was suitable to evaluate the crack with depth more than 1.5 mm. With the increase of radial depth of the cracks, the errors increased for both method, but the error of the echo amplitude was larger. There were many factors related with the inspection accuracy, such as equipment, level of inspector and crack characteristics, and all the factors should be considered.