小径厚壁钢管超声探伤系统设计研究

Ultrasonic Flaw Detection System Design for Small-Diameter Steel Pipe

针对壁厚与外径比大于0.2的小径厚壁无缝钢管提出了一种基于超声波检测的缺陷检测系统,完成了系统的硬件和软件设计,同时为提高系统缺陷的识别效率和准确度,通过分析小径厚壁钢管超声自动探伤系统干扰来源和传播途径,利用改进小波阈值去噪方法来去除混回波信号中的噪声提高回波信号信噪比。实验证明,超声探伤系统能够实现小径厚壁钢管的缺陷检测,小波阈值降噪法可有效去除混在超声回波信号中的各种噪声,大大提高回波信号信噪比。

A non-destructive ultrasonic flaw detection system was proposed and designed for small-diameter steel pipe with thick wall（t/D0.2）,and the hardware and software of this detection system were designed.To improve defect recognition＇s efficiency and accuracy,all sorts of effective anti-interference measures were proposed.They could effectively remove interference signals in ultrasonic echo signal by analyzing interference source and dissemination way of automatic ultrasonic flaw detection system for small-diameter steel pipe with thick wall,and an improved wavelet threshold was proposed to remove mixed noise in the echo signal to improve the echo signal-to-noise ratio at the same time.Experimental results show that the ultrasonic flaw detection system can achieve defect detection of the small-diameter steel pipe with thick wall,and the wavelet threshold de-noising method can effectively remove noise mixed in the ultrasonic echo signal,so the echo signal-tonoise ratio was improved greatly.