钢管端头盲区高速干磁粉成像检测方法

High⁃Speed Dry Magnetic Particle Imaging Detection Method for Blind Area Of Steel Pipe⁃End

在漏磁无损探伤中,钢管端头存在端部效应,会造成钢管端头的检测盲区。为了消除管端缺陷检测的盲区,实现端头盲区的高速检测,提出了一种基于干磁粉成像的视觉检测方法。该方法通过在钢管端部表面施加干法红色磁粉,利用漏磁检测的磁化场形成磁痕,在互补的红色和绿色光源下分别成像,其中红色光源增强、绿色光源减弱磁痕灰度,并通过图像差分消除背景噪声和增强磁痕特征,从而准确地实现钢管端头盲区的快速检测。通过搭建实验平台,开展实验及图像处理耗时分析,结果表明,该方法可以实现对钢管端头盲区的高速有效检测。

In the magnetic flux leakage nondestructive testing,there is an end effect at the steel pipe⁃end,which will cause the detection blind area of the steel pipe⁃end.In order to eliminate the blind area of steel pipe⁃end defect detection and realize high⁃speed inspection of the blind area of the end,a visual inspection method based on dry magnetic particle imaging is proposed.In the method,dry red magnetic particles are ap⁃plied to the surface of the steel pipe⁃end,and the magnetization field detected by the magnetic flux leakage is used to form magnetic marks.Under the complementary red and green light sources,the images are respectively imaged,in which the red light source is enhanced and the green light source is weakened to the grayscale of the magnetic marks,and the background noise and the features of the magnetic marks are eliminated by image difference,so as to accurately realize the rapid detection of the blind area of the steel pipe⁃end.The experimen⁃tal platform is built to carry out the experiment and analyze the time⁃consuming of image processing.The exper⁃imental results show that this method can achieve high⁃speed and effective detection of the blind area at the steel pipe⁃end.