Page 101 - 《应用声学》2021年第1期

第 40 卷 第 1 期 Vol. 40, No. 1
2021 年 1 月 Journal of Applied Acoustics January, 2021

⋄ 研究报告 ⋄

奥氏体不锈钢窄间隙焊缝侧壁未熔合相控阵

超声检测 ∗

张 鑫 林 莉 金士杰 †

(大连理工大学无损检测研究所 大连 116085)
摘要：针对核电站主管道奥氏体不锈钢窄间隙焊缝侧壁未熔合超声检测困难的问题，该文开展基于电子背散
射衍射技术的相控阵超声检测研究，并结合全聚焦方法和相位相干成像方法抑制结构噪声。利用电子背散射
衍射技术建立壁厚 69.5 mm，且同时包含母材和焊缝的奥氏体不锈钢窄间隙焊缝模型。沿焊缝熔合线设置深
度 26.5 mm、高度 3.0 mm 的侧壁未熔合，经过仿真优化确定了中心频率 2.25 MHz、32 阵元以及 45 纵波楔块
◦
的相控阵超声检测参数。仿真和实验检测结果显示，侧壁未熔合检测信噪比相差不超过 0.6 dB，验证了所建模
型的有效性。在此基础上，利用全聚焦方法和相位相干成像方法削弱结构噪声，检测信噪比较相控阵扇扫描图
像分别提升 2.3 dB 和 4.7 dB，且侧壁未熔合深度与高度定量误差均不超过 6.7%。
关键词：奥氏体不锈钢；侧壁未熔合；电子背散射衍射；相控阵超声检测；信号后处理
中图法分类号: TG115.28 文献标识码: A 文章编号: 1000-310X(2021)01-0097-06
DOI: 10.11684/j.issn.1000-310X.2021.01.012
Phased array ultrasonic testing for lack of sidewall fusion in narrow gap welding

of austenitic stainless steel

ZHANG Xin LIN Li JIN Shijie

(NDT & E Laboratory, Dalian University of Technology, Dalian 116085, China)
Abstract: Ultrasonic testing is difficult to detect the lack of sidewall fusion in narrow gap welding of austenitic
stainless steel in nuclear main pipe. In this paper, phased array ultrasonic testing was applied to the detection
of lack of sidewall fusion combining with electron back-scattered diffraction (EBSD) technology, and structural
noise was reduced by use of total focusing method (TFM) and phase coherence imaging (PCI) method. The
model of narrow gap welding of austenitic stainless steel with a thickness of 69.5 mm was established according
to the EBSD map containing welding and base metal. A lack of sidewall fusion with a height of 3 mm and a
depth of 26.5 mm was set along the weld line in the model. The phased array ultrasonic testing was performed
using 32-elements phased array probe with a central frequency of 2.25 MHz and a 45 wedge by simulation
◦
optimization. The difference between the signal-to-noise ratio (SNR) of the lack of sidewall fusion in simulated
and experimental results was no more than 0.6 dB, verifying the validity of the model. On this basis, TFM
and PCI method were introduced to reduce structural noise. In comparison with the S-scan image, the SNRs
of TFM image and PCI image have increment of 2.3 dB and 4.7 dB, respectively. Besides, the measurement
errors of flaw depth and height were both no more than 6.7%.
Keywords: Austenitic stainless steel; Lack of sidewall fusion; Electron back-scattered diffraction; Phased
array ultrasonic testing; Signal post-processing

2020-03-30 收稿; 2020-04-26 定稿
辽宁省 “兴辽英才计划” 项目 (XLYC1902082)
∗
作者简介: 张鑫 (1994– ), 男, 河北承德人, 硕士研究生, 研究方向: 相控阵超声及成像检测研究。
† 通信作者 E-mail: jinshijie@dlut.edu.cn