基于时间反转MUSIC的奥氏体不锈钢超声成像分析  

The ultrasonic inspection of austenitic stainless steels applying the multiple signal classification algorithm

作　　者：吴鹏英[1] 王强[1] 范昕炜[1] 谷小红[2] 

机构地区：[1]中国计量学院质量与安全工程学院,杭州310018 [2]中国计量学院机电工程学院,杭州310018

出　　处：《应用声学》2016年第2期102-108,共7页Journal of Applied Acoustics

基　　金：质检公益性行业科研专项(201410027);国家自然科学基金项目(51275498)

摘　　要：奥氏体不锈钢管道广泛应用于核电及某些化工领域等,但奥氏体不锈钢焊缝缺陷的检测仍然比较困难。在时间反转的基础上,采用DORT算法和MUSIC算法对较低信噪比(-5 dB和-10 dB)的缺陷定位进行仿真分析,在定制的奥氏体不锈钢对接焊缝试块上(300 mm×90 mm×30 mm),采用16阵元超声相控阵探头对缺陷进行检测,引入TR-MUSIC算法对缺陷回波信号进行频域分析。结果表明,低信噪比时,TR-MUSIC算法较TR-DORT算法能更好的抑制旁瓣,使信号能量能更好的聚焦于缺陷;在奥氏体不锈钢焊缝相距25 mm的Φ2mm缺陷(深度为50 mm)检测实验数据基础上,TR-MUSIC算法能够更准确定位缺陷。Austenitic stainless steel has been widely used in nuclear power plant and chemical industries. The problem is that it is difficult to detect the weld defects in coarse grain material. Based on the time reversal method, the decomposition of the time-reversal operator algorithm and multiple signal classification have been used to denoise and to analyze targets detecting performance in simulation with SNR of -5 dB and -10 dB. In the experiment, a 16 element ultrasonic phased array probe has been used to detect the austenitic stainless steel weld block （300 mm×90 mm×30 mm）. The ultrasonic echo signals of flaw have been processed by the TR-MUSIC algorithm for the analysis in the frequency domain. The results indicate that the TR-MUSIC in the side lobe suppression is better than the TR-DORT in low signal-to-noise ratio （-10 dB） signals. Based on the experimental data, austenitic stainless steel weld two side dill holes （apart 25 mm, the depth of 50 ram, and the diameter of 2 ram） have been detected. It is showed that that the TR-MUSIC algorithm can improve the defects detection performance in coarse grain material.

关 键 词：奥氏体不锈钢 焊缝 时间反转 MUSIC算法 超声相控阵 

分 类 号：TG115.28[金属学及工艺—物理冶金]