铁磁材料电导率脉冲涡流测量方法研究

Electrical conductivity is an important parameter to characterize the conductivity property of metal materials. Electrical conductivity measurement of ferromagnetic metallic materials is extremely useful for materials sorting, alloy materials identification, hardness detecting and heat treatment monitoring. The main purpose of this project is to develop a pulsed eddy current testing method for electrical conductivity measurement of ferromagnetic metallic materials. Without pretreatment on the non-conductive coating of the test specimen, the electrical conductivity of ferromagnetic metallic plates, pipes and spheres can be measured, and does not depend on calibration standards. The theoretical research of this project is as follows: the establishing and solving of the mathematic model of pulsed eddy current electromagnetic field on ferromagnetic components with remanent magnetism; the inversion algorithm for electrical conductivity of ferromagnetic components established via the calculated and measured values of time-domain induced voltage signal. Based on the results of the theoretical research, an innovative pulsed eddy current testing instrument for electrical conductivity measurement of ferromagnetic metallic materials will be developed. The results obtained in these studies will be conducive to: gaining an insight into the physical nature of the pulsed eddy current testing method; promoting the development and application of pulsed eddy current testing technology on ferromagnetic metallic materials; and proposing a nondestructive and non-contacting method for electrical conductivity measurement of ferromagnetic metallic materials in industry.

电导率是表征材料导电性能的一个重要参数，通过无损测量铁磁材料的电导率，可对不同的铁磁材料进行分拣和识别，间接判断材料的硬度和热处理状态等。本项目研究铁磁性金属材料电导率的脉冲涡流无损测量方法，在无须去除材料外涂层和包覆层、无需标准试件的前提下，测量平板、管状和球状铁磁构件的电导率。主要研究：剩磁状态下铁磁构件脉冲涡流电磁场模型的建立与解析方法，利用时域感应电压的测量值与理论计算值建立反演模型来确定铁磁构件电导率的反演方法，并根据理论研究结果，试制出铁磁性金属材料电导率脉冲涡流测量装置。本项目的研究有助于深入了解脉冲涡流检测方法的物理本质，有助于促进铁磁构件脉冲涡流检测技术的发展，有可能为工业生产中铁磁性金属材料电导率提供一种非接触、无损的测量方法。

电导率是表征材料导电性能的一个重要参数，通过无损测量铁磁材料的电导率，可对不同的铁磁材料进行分拣和识别，间接判断材料的硬度和热处理状态等。本项目研究铁磁性金属材料电导率的脉冲涡流无损测量方法，在无须去除材料外涂层和包覆层、无需标准试件的前提下，测量平板、管状和球状铁磁构件的电导率。本项目研究的主要内容有：研究了剩磁状态下铁磁构件脉冲涡流电磁场模型的建立与解析方法；研究了平板、管状和球状铁磁构件在脉冲磁场激励下的涡流电磁场解析方法；利用时域感应电压的测量值与理论计算值建立反演模型来确定铁磁构件的电导率；利用四探针法验证脉冲涡流方法测量铁磁性金属材料电导率的可靠性；根据理论研究结果，试制出铁磁性金属材料电导率脉冲涡流测量装置。在此基础上，本项目进一步研究了多层导体参数的涡流检测方法。本项目的研究有助于深入了解脉冲涡流检测方法的物理本质，有助于促进铁磁构件脉冲涡流检测技术的发展，为工业生产中铁磁性金属材料电导率提供一种非接触、无损的测量方法。