奥氏体不锈钢焊缝超声回波信号的匹配追踪处理  

Matching track process of ultrasonic echo signal in austenitic stainless steel welds

作　　者：龚思璠 王强 谢正文[1] 翟永军 胡栋 

机构地区：[1]中国计量大学质量与安全工程学院,浙江杭州310018 [2]山东省特种设备检验研究院泰安分院,山东泰安271000

出　　处：《声学技术》2017年第3期252-256,共5页Technical Acoustics

基　　金：质检公益性行业科研专项(201410027)

摘　　要：研究了奥氏体不锈钢焊缝组织的金相显微结构及其对超声检测的影响,利用超声相控阵检测技术对定制的奥氏体不锈钢对接焊接接头对比试块中不同深度(10、30、50、70 mm)、φ2 mm×30 mm的横通孔缺陷进行了不同波型(横波和纵波)的检测,采用匹配追踪后处理方法对超声回波信号进行了处理。结果显示:奥氏体不锈钢焊缝组织结构复杂,晶粒粗大,各向异性明显,对超声检测产生严重的声能衰减,纵波检测奥氏体不锈钢焊缝中较深缺陷(50 mm)的能力强于横波检测,且匹配追踪对奥氏体不锈钢焊缝超声检测回波信号的处理不仅能有效抑制噪声信号、提高信噪比,还能提取出被淹没在噪声信号中的缺陷信号。Metallographic microstructure in the welds of Austenitic stainless steel and its influences on ultrasonic in- spection are studied in this paper. By the technique of ultrasonic phased array detection, waveforms inspection （T-wave and P-wave） are conducted for a set ofФ 2 mm×30 mm horizontal hole defects at different depths of 10 mm, 30mm, 50 mm and 70 mm along the welded joints of the customized Austenitic stainless steel specimens. Besides, the ultrasonic echo is processed by post-processing method of matching track. The results indicate that Austenitic stainless steel weld is complicated in organization structure with coarse grains and obvious anisotropy, which causes heavy sound energy attenuation during ultrasonic detection. The capability of using longitudinal wave （P-wave） to detect deeper defect （50 mm） in Austenitic stainless steel weld is better than that of using transverse wave （T-wave）. Additionally, after the ultrasonic echo is processed by matching track technique, both the noise is effectively suppressed, and the useful defect signal kept. Moreover, the defect signal submerged in the noise is extracted and the SNR increases apparently, which benefits the extraction of the defect information.

关 键 词：奥氏体不锈钢 焊缝显微组织 超声相控阵 匹配追踪 缺陷信号 

分 类 号：TG115.28[金属学及工艺—物理冶金]