A STUDY OF NONDESTRUCTIVE TESTING WITH MAGNETIC CHARACTERISTIC MEASUREMENT METHOD

In this research，I investigated that establishment of a method estimate the metals fatigue as its object by measuringthe magnetic characteristics. A single sheet tester method by using H-coil method is investigated.originally,它必须measure a fatigue with using condition， But this study for the purpose of obtain thefundamental时间,因此produce the equipment which can measure the single sheets that size are 40**140mm. the plot-typesingle sheet tester with double-yoke vertical was made. Magnetic flux density was measured byb-coil,and magnetic field intensity was measured by H-coil.The fatigue was given by the equipment which wasmade by The one side of The sample is fixed and another side was vibrated by The equioment. The频率是关于5到10hz .频率是计数的数bounter.Measurement频率为100,1k和10khz . Exciting coil waa designed to measure thecharacteristics at maximum magnetic flux density 1.4T in 100hz . The samples are Si-Fe steel，steel and SPCD (steel Plate Cold Deep, down).The summarise of this study is follows；这是可能的，在磁性材料表面分析，这是必要的。crack laid to be perpendicular. Change of the magnetic characterisitics according to the fatigue. .但它不是很清楚the fatigue and the magnetic characteristics。

In this research, I investigated that establishment of a method estimate the metals fatigue as its object by measuring the magnetic characteristics. A single sheet tester method by using H-coil method is investigated. Originally, it needs to measure a fatigue with using condition. But this study for the purpose of obtain the fundamental date, so produce the equipment which can measure the single sheets that size are 40**140mm.The plot-type single sheet tester with double-yoke vertical was made. Magnetic flux density was measured by B-coil, and magnetic field intensity was measured by H-coil.The fatigue was given by the equipment which was made by us. The one side of the sample is fixed and another side was vibrated by the equioment. the frequency of the vibration is about 5 to 10 Hz. The number of frequent is counted by bounter.Measurement frequency is 100,1k and 10kHz. Exciting coil waa designed to measure the characteristics at maximum magnetic flux density 1.4T in 100Hz. The samples are Si-Fe steel, SK steel and SPCD (Steel Plate Cold Deep, down).The summarise of this study is as follows ;・It is possible that detect of crack at surface of magnetic materials. It is necessary that the crack laid to be perpendicular.・Change of the magnetic characterisitics according to the fatigue. But it is not clear between the fatigue and the magnetic characteristics.