作者：徐煦源, 涂君, 张旭, 宋小春

作者单位：湖北工业大学机械工程学院, 湖北 武汉 430068

关键词：电磁超声;测厚;线圈特性;实验研究

摘要：

为解决电磁超声检测信噪比低，为电磁超声线圈设计提供参考依据，该文针对常用的测厚电磁超声线圈开展一系列实验研究。首先对比螺旋线圈、矩形线圈、吕形线圈和蝶形线圈4种线圈结构的测厚反射回波信噪比，实验对象采用阶梯型钢板，结果发现螺旋线圈对于厚板测厚效果最佳，信噪比平均值达到14 dB以上。然后研究上述线圈的幅频特性，实验结果表明激励频率为1.8 MHz时，所有线圈的信噪比达到10 dB以上。最后通过线圈作用范围实验，得出不同类型线圈的主要作用区域也不同的结论。

Study on characteristic of the common electromagnetic acoustic coils for thickness measurement of steel plates
XU Xuyuan, TU Jun, ZHANG Xu, SONG Xiaochun
School of Mechanical Engineering, Hubei University of Technology, Wuhan 430068, China
Abstract: In order to solve the low signal-to-noise ratio of electromagnetic acoustic testing and provide a reference for the design of electromagnetic ultrasonic coils, a series of experimental researches are carried out on commonly used electromagnetic acoustic coils for thickness measurement. Firstly, by comparing the thickness and reflection echo signal-to-noise ratios of the four coil structures of spiral coil, square coil, double-rectangular coil and butterfly coil, the experimental object uses a stepped steel plate. The results shows that the average signal-to-noise ratio is above 14 dB. Next, the amplitude-frequency characteristics of the above coils are studied. The experimental results show that when the excitation frequency is 1.8 MHz, the signal-to-noise ratio of all the coils is above 10 dB. Finally, through the experiment of the range of the coil, it is concluded that the main areas of action of different types of coils are also different.
Keywords: electromagnetic acoustic;thickness measurement;coil characteristics;experimental study
2020, 46(4):143-147  收稿日期: 2019-11-01;收到修改稿日期: 2019-12-21
基金项目: 国家自然科学基金（51707058，51807052）；湖北省重大技术创新项目（2018AAA034）
作者简介: 徐煦源(1995-),男,江西樟树市人,硕士研究生,专业方向为无损检测新技术
参考文献
[1] 邱佳明, 丁汉绅, 王淑娟. 电磁超声钢板测厚装置中脉冲电磁铁的设计[J]. 中国测试, 2018, 44(5):77-82
[2] 康宜华, 涂君, 杨芸, 等. 一种简便的电磁超声测厚实现方法探究[J]. 自动化仪表, 2012, 33(10):83-85
[3] HUANG S L, ZHAO W, ZHANG Y S, et al. Study on the lift-off effect of EMAT[J]. Sensors & Actuators:A. Physical, 2009, 153(2):218-221
[4] MIKHAILOV A V, GOBOV Y L. An electromagnetic acoustic transducer with pulsed biasing[J]. Russian Journal of Nondestructive Testing, 2015, 51(8):467-485
[5] PEI C X, XIAO P, ZHAO S Q, et al. Development of a flexible film electromagnetic acoustic transducer for nondestructive testing[J]. Sensors and Actuators A:Physical, 2017(258):68-73
[6] 罗垚, 武新军. 电磁超声横波测厚传感器研究[J]. 化工自动化及仪表, 2019, 46(9):709-712
[7] 翟国富, 汪开灿, 王亚坤, 等. 螺旋线圈电磁超声换能器解析建模与分析[J]. 中国电机工程学报, 2013, 33(18):147-154
[8] MIRKHANI K, CHAGGARES C, MASTERSON C, et al. Optimal design of EMAT transmitters[J]. NDT&E International, 2004, 37(3):181-193
[9] 唐东林, 侯军. 基于Halbach原理的电磁超声换能器永磁铁设计[J]. 传感技术学报, 2018, 31(10):33-37
[10] JIA X J, OUYANG Q, ZHANG X. An improved design of the spiral-coil EMAT for enhancing the signal amplitude[J]. Sensors, 2017, 17(5):1106
[11] 张金, 赵亮, 石文泽, 等. 曲折线圈电磁超声换能器激励性能优化设计[J]. 传感技术学报, 2019, 32(8):1182-1188
[12] 杨亮. 基于电磁超声的金属板测厚系统研制[D].沈阳:沈阳工业大学, 2017.
[13] 黄凤英, 周正干. 静态偏置磁场对电磁超声换能器灵敏度的影响[J]. 机械工程学报, 2011, 47(10):1-7
[14] 王丽, 武新军, 汪玉刚. 钢板表面球形孔电磁超声检测信号特性分析[J]. 中国测试, 2014, 40(5):17-20