Abstract—The paper presents the results of studying the detectability of surface volumetric defects by ultrasonic method of nondestructive testing. The possibility of using Rayleigh surface waves excited by an electromagnetic-acoustic transducer (EMAT) for these purposes is considered. Blind vertical drillings of various diameters and depths were used as artificial defects to simulate defects in low carbon steel samples. Based on the results of measurements, the dependence of the amplitude of the received signals on drilling parameters has been constructed. When statistically processing the results, the signal-to-noise ratio during the excitation of the Rayleigh wave with the help of the EMAT on defect-free areas of samples was taken into account. Optimal models of the distribution of signal amplitudes were determined to construct the curves of probability of detection (PoD) of a defect. Under the conditions of the experiments, based on the PoD curves constructed, conclusions have been drawn about the minimum dimensions of surface volumetric defects identified with 90% probability with allowance for the confidence interval of 90% and about the possibility of adjusting the parameters of ultrasonic testing by signals reflected from vertical drillings.

摘要—本文介绍了通过无损检测的超声波方法研究表面体积缺陷的可检测性的结果。考虑使用由电磁声换能器 (EMAT) 激发的瑞利表面波用于这些目的的可能性。使用各种直径和深度的盲垂直钻孔作为人工缺陷来模拟低碳钢样品中的缺陷。根据测量结果，构建了接收信号幅度对钻井参数的依赖性。在对结果进行统计处理时，在 EMAT 的帮助下，瑞利波激发期间的信噪比被考虑到样品的无缺陷区域。确定信号幅度分布的最佳模型以构建缺陷检测概率 (PoD) 曲线。在实验条件下，根据所构建的 PoD 曲线，得出了在允许 90% 置信区间的情况下，以 90% 的概率识别表面体积缺陷的最小尺寸以及调整超声波参数的可能性的结论。通过垂直钻孔反射的信号进行测试。