基于电磁超声表面波干涉增强的钢板表面检测  

Steel Plate Surface Inspection Based on Interference Enhancement of Rayleigh Waves Generated by EMAT

作　　者：王丽[1] 武新军[1] 汪玉刚[1] 

机构地区：[1]华中科技大学机械科学与工程学院,武汉430074

出　　处：《无损检测》2014年第4期5-7,13,共4页Nondestructive Testing

基　　金：国家重大科学仪器设备开发专项资助项目(2012YQ09017502)

摘　　要：电磁超声检测在具有非接触优势的同时,存在换能效率低、信号噪声大的不足。利用电磁超声无需耦合剂对声波传播无干扰的特点,研究了基于声波干涉增强的钢板表面缺陷超声检测方法。在制作了一种用于扫查检测的电磁超声表面波传感器的基础上,搭建了相应的试验平台,对钢板表面人工刻槽进行了检测。试验结果表明：当传感器与刻槽满足一定的位置关系时,超声信号将增强10%-20%。利用此现象进行缺陷评判,可避免分析相对较弱的缺陷回波,为电磁超声检测技术的应用提供了一种新方法。Electromagnetic acoustic testing has been widely used in many industrial fields due to its non-contact characteristic,while it＇s still restricted by the low efficiency and large signal noise.This paper studies a different ultrasonic method for steel plate surface inspection based on interference enhancement of Rayleigh waves.An electromagnetic acoustic transducer（EMAT）is used to generate the Rayleigh wave because of its advantage of no couplant interference with the acoustic wave propagation.With the self-developed EMAT that can be used for scanning inspection,aplatform is set up to conduct the experiment of slots testing.Results show that the ultrasonic signal enhances 10% -20% when the transducer is placed in certain location from slots and this provides the possibility of using the enhancement to evaluate defects without analyzing the relatively weak defect reflections.

关 键 词：电磁超声 表面波 干涉增强 钢板 刻槽 

分 类 号：TG115.28[金属学及工艺—物理冶金] TB553[金属学及工艺—金属学]