基于脉冲涡流检测技术的铁磁性材料厚度的测量  

Thickness measurement of ferromagnetic material based on pulsed eddy current testing technology

作　　者：王健[1] 傅迎光[1] 孙明璇[1] 刘再斌[2] 范智勇[2] 石坤[2] 

机构地区：[1]北京交通大学理学院,北京100044 [2]中国特种设备检测研究院,北京100013

出　　处：《北京交通大学学报》2012年第6期133-136,共4页JOURNAL OF BEIJING JIAOTONG UNIVERSITY

基　　金：国家质检总局科研专项基金资助项目(201110028-04)

摘　　要：脉冲涡流检测是一种新型的无损检测技术,脉冲涡流产生磁场的频谱宽、穿透能力强,检测时可以获得更多的缺陷信息.铁磁材料的磁导率很高,其测量厚度是通过检测电压的特征衰减时间来确定的,而特征衰减时间与厚度的关系建立在被测试件比检测线圈大得多的基础上.当被测试件比较小时,就不可避免地出现测量误差.本文根据脉冲涡流检测的工作原理,计算了铁磁试件的大小、提离高度和试件厚度对测量的影响.结果表明:试件越小,测量的相对误差越大;试件较小时提离高度越大、试件的厚度越大,产生的相对误差也越大,相对于提离高度,试件厚度对测量结果有更大的影响.Pulsed eddy current（PEC） detecting is a new kind of nondestructive testing technique.PEC can generate a magnetic field which has wide spectrum and strong penetration ability.More defect information can be gotten by PEC detecting.Ferromagnetic materials have high permeability.The measured thickness is determined by the characteristic decay time of the induction voltage.The relationship between the characteristic decay time and the thickness is based on the measured specimen size much larger than the detecting coil size.If the specimen size is smaller,the measurement error is unavoidable.Based on the principle of PEC detecting,effects of the ferromagnetic specimen size,lift-off height and specimen thickness on the measurements are calculated.The results show that the relative errors increase with the decrease of specimen size,and with the increase of the lift-off height and the thickness when the specimen size is smaller.Specimen thickness has a greater impact on the measurement result than the lift-off height does.

关 键 词：脉冲涡流检测 铁磁介质 测厚 特征衰减时间 测量相对误差 

分 类 号：TG115.28[金属学及工艺—物理冶金]