基于深度重采样的奥氏体不锈钢焊缝超声TOFD检测技术研究

Research on TOFD Technique for Austenitic Stainless Steel Welds Based on Depth Resampling

针对传统奥氏体不锈钢焊缝超声TOFD检测技术获取的检测信号信噪较低、难以有效判定缺陷衍射波的问题,本文提出了深度重采样超声TOFD检测技术,并通过试验分析了技术中探头角度、叠加次数的控制要点,检测了该技术提升信噪比的效果。实验结果表明,当控制斜楔角度为60°,叠加次数为8次时,本文提出的技术可取得较高的检测信号信噪比,对比常规超声TOFD检测信号,平均信噪比提高了67.5%。

In view of the low signal-to-noise ratio of the co nventional ultrasonic TOFD detection technique for austenitic stainless steel welds,it is difficult to identify the diffraction waves effectively,this paper proposes a depth resampling ultrasonic TOFD detection technology,and through the experimental analysis of the technology of the probe angle,the superposition of the number of times of the control points,detects of the technology to improve the effect of the signal-to-noise ratio.The experimental results show that when the angle of the slanting wedge is controlled to be 60°and the number of superimpositions is 8 times,the proposed technique in this paper can achieve a high signal-to-noise ratio of the detected signals,and the average signal-to-noise ratio is improved by 67.5%compared with that of the conventional ultrasonic TOFD detected signals.