• CN：11-2187/TH
  • ISSN：0577-6686
机械工程学报

机械工程学报 ›› 2017, Vol. 53 ›› Issue (12): 52-59.doi: 10.3901/JME.2017.12.052

• 承压设备的无损检测与评价 • 上一篇    下一篇

基于幅度加权编码激励的不锈钢焊缝TOFD成像检测研究

丛森1,2, 刚铁2, 张佳莹2   

  1. 1. 中国工程物理研究院电子工程研究所 绵阳 621900;
    2. 哈尔滨工业大学先进焊接与连接国家重点实验室 哈尔滨 150001
  • 出版日期:2017-06-20 发布日期:2017-06-20
  • 作者简介:

    丛森，女，1987年出生，博士，助理研究员。主要研究方向为焊接无损检测评价。

    E-mail：congsen305 @163.com

    刚铁(通信作者)，男，1952年出生，博士，教授，博士研究生导师。主要研究方向为焊接质量评价与无损检测。

    E-mail：gangt@hit.edu.cn

  • 基金资助:
    * 国家自然科学基金资助项目(51175113， 51575134); 20160605收到初稿，20170105收到修改稿;

Ultrasonic Time-of-flight Diffraction Imaging Inspection for Stainless Steel Welds Based on Amplitude Weight Coded Exciting

CONG Sen1,2, GANG Tie2, ZHANG Jiaying2   

  1. 1. Institute of Electronic Engineering, China Academy of Engineering Physics, Mianyang 621900；
    2. State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001
  • Online:2017-06-20 Published:2017-06-20

PDF

260

摘要：

通过Hamming窗加权方法设计了幅度加权调频编码激励信号，将这种新型的激励方法与TOFD (Time-of-flight diffraction) 检测方法相结合，综合提高了粗晶奥氏体不锈钢焊缝缺陷检测的时间分辨力、检测信噪比和缺陷定量定位精度，有效改善了粗晶焊缝超声检测中的难点问题。为分析设计的幅度加权调频编码激励信号的检测能力，针对奥氏体不锈钢母材试件和焊缝试件中的横孔缺陷，采用5 MHz探头分别进行了编码激励和常规激励的TOFD成像检测对比试验，结果表明：在相同的检测条件下，幅度加权调频编码激励可提高了图像和信号质量，使检测信号中的杂波和噪声得到抑制，缺陷上端和下端衍射波被准确区分，使各波形的时间宽度降低了30%，有效提高了TOFD检测的时间分辨力;获得的缺陷定位定量测量的平均相对误差为3.8%，较常规激励降低了47%，这种激励方法可在不提高激励电压和增益条件下，使不锈钢焊缝中缺陷检测的信噪比达16 dB以上，较常规激励平均提高了7 dB。

关键词: 奥氏体不锈钢焊缝, 编码激励, 幅度加权, 超声TOFD成像检测

Abstract:

An amplitude weight frequency modulated coded excitation signal is designed by Hamming window weight method, and the novel excitation method is combined with time-of-flight diffraction(TOFD) inspection technique, which can make the time resolution, signal to noise ratio(SNR), defect positioning and sizing accuracy be enhanced comprehensively, and can effectively improve the problem of ultrasonic inspection for coarse-grained welds. In order to analyze the inspection ability of the amplitude weight frequency modulated coded excitation signal designed, the TOFD imaging inspection experiments excited by coded signal and conventional signal are carried out by using the 5 MHz transducers for the side-drilled holes in the austenitic stainless steel base metal and welds, the results show that in the same inspection conditions, amplitude weight frequency modulated coded excitation can enhance the quality of images and signals, and make the clutter and noise be suppressed, the diffracted waves of defect upper and lower tips be accurately distinguished, the duration of the waves be decreased 30%, the time resolution of TOFD testing be increased; the average relative error of defect positioning and sizing is 3.8%, which decreases 47% compared with conventional excitation. The excitation method can make the inspection SNR more than 16 dB, higher 7 dB than conventional excitation.

Key words: amplitude weight, austenitic stainless steel welds, coded excitation, ultrasonic time-of-flight diffraction imaging inspection

版权所有 © 2019 《机械工程学报》编辑部 | 京icp备05055788号-40