Abstract

We propose to use the shape of the envelope of the spectrum of the collection of pulses received from metal products by a straight-beam electromagnetic-acoustic transducer as a new criterion for the presence of a defect at the bottom surface of the product. A new flaw detection method to test pipes, sheets, and shells has been developed, which includes excitation and reception of packet ultrasonic pulses with a given duration and carrier frequency, determining the shape of the envelope of the spectrum of the total received signal, comparing the resulting spectrum envelope with the envelope of the spectrum of bottom signals in a defect-free reference section, and making a decision about the presence of a defective metal section based on the results of comparison. It has been experimentally proved that the developed method is effective both in the presence and in the absence of echoes reflected from defects in a realization. The effectiveness of the developed method has been confirmed experimentally by identifying defective areas at the bottom surface of a product.

中文翻译：

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非接触式光谱表达法检测金属制品的腐蚀损伤

摘要

我们建议使用直束电磁声换能器从金属产品接收到的脉冲集合的频谱的包络形状，作为产品底部表面缺陷存在的新标准。已经开发出一种新的探伤方法来测试管道，板材和壳体，包括激发和接收具有给定持续时间和载频的包超声脉冲，确定总接收信号频谱的包络形状，比较得到的频谱包络与无缺陷参考部分中底部信号频谱的包络，并根据比较结果确定是否存在有缺陷的金属部分。实验证明，所开发的方法在存在和不存在缺陷反射回波的情况下都是有效的。通过确定产品底部表面的缺陷区域，实验已证实了所开发方法的有效性。