Pulsed Magnetic Flux Leakage Testing for Defect Detection on Steel-pipe

摘要

Magnetic flux leakage techinique(MFL) have been widely used for steel products detection. The main magnetization methods are in form of DC、AC and permanent magnet. We presents a pulsed alternating current magnetizing method. The probe is driven with square waveform and the rich frequency components can provide much information about near surface or sub-surface defect of sample. The principle of pulsed magnetic flux leakage testing (PMFL) is introduced.The PMFL testing system have been established to examine the steel pipe of different depth defects.The time domain transient response signal of PMFL is analyzed. The experiment results shows that PMFL can provide additional information about the defect size,and has the advantage of fast speed and quantification,this makes this method have the broad using foreground in the testing of steel pipe.