漏磁检测技术的研究与发展现状

Review of Research and Development of Magnetic Flux Leakage Technique

漏磁检测技术是一种用来检测铁磁性材料表面腐蚀、凹坑、凹槽、裂纹等缺陷的电磁无损检测方法,已被广泛应用于大型常压储罐、压力管道及元件和钢丝绳的检测。本文给出了漏磁检测技术的原理及特点;综述了国内外漏磁检测技术的理论研究和应用研究现状及漏磁检测信号的放大、滤波、处理方式和缺陷识别等处理方法;分析了影响漏磁检测结果的磁化强度、提离、扫查速度、缺陷位置及形状、表面状态等各种影响因素;介绍了国内外钢管(棒)生产线自动化漏磁检测设备、钢丝绳漏磁检测仪、储罐底板漏磁检测仪、管道外部漏磁检测仪、管道内漏磁检测器等仪器设备和相应的检测标准;最后指出漏磁检测技术目前仍然存在的问题和发展趋势。

Magnetic flux leakage（MFL） testing technique is a kind of electromagnetic nondestructive testing（NDT） methods, which is used to detect defects on ferromagnetic materials, such as corrosion, pit, notch, crack and etc. It has been widely applied for testing of large atmospheric tanks, pressure vessel, pressure piping and wire rope. In this paper, the principle and features of MFL testing technique are introduced. The research and application progress and signal processing methods such as amplification, filtering and defect identification of MFL technique are overviewed. The influence factors such as magnetization, lift off, scanning speed, defect location and shape, surface condition and so on are analyzed. The domestic and foreign steel pipe（rod） production line automatic MFL testing equipment, wire rope MFL instrument, tank floor MFL instrument, pipeline external MFL instrument, pipeline inner MFL detector and the corresponding testing standards are introduced. Finally, the existing problems and development trend of MFL testing technology are pointed out.