有包覆层铁磁试件的脉冲涡流检测  

Pulsed Eddy Current Detecting for Ferromagnetic Specimen with a Cladding Layer

作　　者：傅迎光[1] 王健[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 发光与光信息技术教育部重点实验室 光信息科学与技术研究所,北京100044 [2]中国特种设备检测研究院,北京100013

出　　处：《测试技术学报》2013年第2期142-147,共6页Journal of Test and Measurement Technology

基　　金：国家质检总局科研专项基金资助项目(201110028-04)

摘　　要：测量由钢板制作的压力容器和管道的壁厚,可以了解其腐蚀程度.用脉冲涡流检测钢板等铁磁材料的厚度时,由保护层和保温层构成的包覆层会对测厚结果产生影响.根据脉冲涡流检测的工作原理,使用有限元法,对有包覆层铁磁试件的厚度测量进行了仿真研究,重点分析了覆盖层对测量结果的影响.研究结果表明:包覆层对测量的影响与保护层材料、试件厚度和保温层厚度有关;对试件厚度测量范围的影响铝皮比铁皮保护层大,使用铝皮保护层时,不能测量厚度小于6mm的试件;试件与保温层越厚,测量误差越小,试件的厚度大于10 mm,保温层的厚度大于50mm时,测量结果不再受保覆层的影响.The extent of corrosion can be obtained by measuring the wall thicknesses of pressure vessels and pipes made of steel plates. When measuring the thicknesses of steel plates and other ferromagnetic materials by using pulsed eddy current technology, the cladding layer which consists of a protective layer and an insulat- ing layer could affect the measurement results. In this paper, we mainly study this problem. According to the principle of pulsed eddy current detecting, using the finite element method, we simulated the thickness mea- surement of the ferromagnetic specimen with cladding layer, and emphatically analyzed the effects of the clad- ding layer on the measurement. The effects of the cladding layer on the measurement are related to the protec- tive layer material, the specimen and insulating layer thickness. The effects of aluminum sheet on the mea- surement range of the specimen thickness are larger than that of iron sheet. When using aluminum sheet as protective layer, we cannot measure the thickness if the specimen is less than 6 mm thickness. The smaller thickness of the specimen and insulating layer is, the smaller measurement error is. When the specimen thick- ness is more than 10 mm, and insulating layer thickness is more than 50 mm, the effect of the cladding layer on the measurement can be neglected.

关 键 词：脉冲涡流检测 包覆层 铁磁介质 测厚 特征衰减时间 

分 类 号：TG115.28[金属学及工艺—物理冶金]