TOFD testing signal noise reduction technology for stainless steel welds based on depth resampling superposition

The coarse columnar crystal structure of the austenitic stainless steel weld leads to the low signal-to-noise ratio of the conventional TOFD detection signal, and it is difficult to determine the defect diffraction wave in the detection signal. In order to improve the signal-to-noise ratio of the detection signal, based on the difference between the defect diffraction wave signal and the weld structure noise, a deep resampling and superposition algorithm is proposed and a test is carried out.The research results show that, compared with the phase distribution of the defect diffraction wave signal, the phase distribution of the structure noise is random; the deep resampling superposition technology can effectively suppress the structure noise of the tissue and improve the signal-to-noise ratio of the detection signal, playing an important role in improving the TOFD inspection ability of austenitic stainless steel welds.