奥氏体不锈钢焊缝粗大的柱状晶组织会导致常规TOFD（超声波衍射时差法）检测信号的信噪比较低，检测信号中的缺陷衍射波较难判定。为提高检测信号信噪比，基于缺陷衍射波信号与焊缝组织结构噪声的差异，提出了深度重采样叠加算法并进行检测试验。研究结果表明，与缺陷衍射波信号基本一致的相位分布相比，结构噪声的相位分布具有随机性；深度重采样叠加技术可有效抑制组织结构噪声，提高检测信号信噪比，对于提高奥氏体不锈钢焊缝的TOFD检测能力具有重要作用。

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.