厚壁奥氏体不锈钢焊缝双晶纵波面阵探头矢量相干全聚焦成像研究  

Research on vector coherence factor-based total focusing imaging for thick-walled austenitic stainless steel welds via dual matrix longitudinal wave array probe

作　　者：杨宸旭 严宇 刘梓昱 王俊龙 马志远[1] 杨会敏 刘伟达 张东辉 林莉[1] YANG Chenxu;YAN Yu;LIU Ziyu;WANG Junlong;MA Zhiyuan;YANG Huimin;LIU Weida;ZHANG Donghui;LIN Li(NDT&E Laboratory,Dalian University of Technology,Dalian 116024,China;Nuclear Industry Research and Engineering Co.,Ltd.,Beijing 101601,China;Nuclear Industry 23 Construction Co.,Ltd.,Beijing 101300,China)

机构地区：[1]大连理工大学无损检测研究所,辽宁大连116024 [2]核工业工程研究设计有限公司,北京101601 [3]中国核工业二三建设有限公司,北京101300

出　　处：《压力容器》2024年第12期60-66,共7页Pressure Vessel Technology

摘　　要：针对厚壁奥氏体不锈钢焊缝全聚焦(TFM)成像信噪比低、影响缺陷辨识的问题,开展一发一收纵波(TRL)面阵探头结合矢量相干因子(VCF)的加权成像研究。在厚度76 mm奥氏体不锈钢焊缝试块中加工深度为10,30,50,70 mm,直径为3.2 mm横通孔缺陷,利用中心频率2.25 MHz、阵元排布16×4×2的TRL探头采集全矩阵数据。根据探头的二维阵列双模块结构,建立基于三维声束传播路径的延时叠加计算法则,提取信号瞬时相位构建VCF,并利用权重因子重构成像数据矩阵,形成针对厚壁奥氏体不锈钢焊缝的TRL-TFM-VCF成像方法。试验结果表明,相比于扇形扫描和全聚焦成像,TRL-TFM-VCF方法焊缝近表面(深度10 mm)缺陷信噪比分别提升了9.98 dB和6.37 dB;近底面(深度70 mm)缺陷信噪比分别提升了8.33 dB和3.00 dB;阵列性能参数分别降低了4.74和4.85。该方法可有效提升厚壁奥氏体不锈钢焊缝超声检测信噪比和对缺陷的定位精度。To address the low signal-to-noise ratio(SNR)in total focusing method(TFM)imaging of thick-walled austenitic stainless steel welds,which hinders defect identification,this study proposes a weighted imaging method combining a transmitreceive longitudinal wave(TRL)dual matrix array probe with a vector coherence factor(VCF).A 76 mm-thick austenitic stainless steel weld test block was fabricated with side-drilled holes(SDHs)of 3.2 mm diameter at depths of 10,30,50,and 70 mm.Full matrix capture(FMC)data were acquired using a TRL probe with a center frequency of 2.25 MHz and a 16×4×2 element configuration.Based on the dual-module structure of the 2D array probe,a delay and sum(DAS)algorithm incorporating 3D acoustic beam propagation paths was established.The instantaneous phase of signals was extracted to construct the VCF,and the imaging data matrix was reconstructed using a weighting factor,forming the TRL-TFM-VCF imaging method tailored for thickwalled austenitic stainless steel welds.Experimental results demonstrate that,compared to sector scanning and conventional TFM,the TRL-TFM-VCF method improves the SNR of near-surface defects(10 mm depth)by 9.98 dB and 6.37 dB,respectively,and enhances the SNR of near-root defects(70 mm depth)by 8.33 dB and 3.00 dB,respectively.The array performance parameter(APP)is reduced by 4.74 and 4.85,indicating optimized imaging quality.This method effectively enhances ultrasonic inspection SNR and defect localization accuracy for thick-walled austenitic stainless steel welds.

关 键 词：奥氏体不锈钢焊缝 双晶面阵探头 全聚焦成像 矢量相干因子 

分 类 号：TH49[机械工程—机械制造及自动化] TG115.28[金属学及工艺—物理冶金] TG441.7[金属学及工艺—金属学]