CAJ | 학술논문

采用磁记忆技术研究了石化企业铁磁性构件典型缺陷（如裂纹、未焊透、错边、气孔、偏析等）的灵敏度和信号特征。结果表明：该技术在检测上述缺陷时有较高的灵敏度，磁信号特征与检测方向和缺陷主平面间相对夹角有关。当两者垂直时，法向磁场强度Hp （y）在缺陷正上方有过零点；当两者平行时，对称置于缺陷主平面两侧的通道的Hp （y）极性相反，且变化趋势相对。但不管夹角如何，磁记忆信号均在裂纹部位出现突变，不易引起漏检。在偏析严重区域，磁记忆信号沿检测位移出现波峰或波谷变化，这为检测铁磁性材料偏析严重部位提供了一种新的检测手段。
채용자기억기술연구료석화기업철자성구건전형결함（여렬문、미한투、착변、기공、편석등）적령민도화신호특정。결과표명：해기술재검측상술결함시유교고적령민도，자신호특정여검측방향화결함주평면간상대협각유관。당량자수직시，법향자장강도Hp （y）재결함정상방유과영점；당량자평행시，대칭치우결함주평면량측적통도적Hp （y）겁성상반，차변화추세상대。단불관협각여하，자기억신호균재렬문부위출현돌변，불역인기루검。재편석엄중구역，자기억신호연검측위이출현파봉혹파곡변화，저위검측철자성재료편석엄중부위제공료일충신적검측수단。
In this study,we investigated the characteristic of magnetic memory signals on typical defects (such as flaw,incomplete penetration,misalignment,air hole and segregation )using magnetic memory technique.The results suggest magnetic memory testing has high sensitivity on above defects;especially, the technique is sensitive to the angle between the testing direction and the principle plane of defects.The normal component of magnetic field Hp(y)has a cross zero point right above defects and presenting sign curve when tested perpendicular to the principle plane of defects;in contrast,Hp (y),obtained from the sensor symmetrically placed at the opposite side of the principle plane of defects,has different polarities and varied oppositely as tested along the defects.However,the magnetic memory signals changed abruptly at the crack area no matter the angle between testing direction and crack,thus the problem of undetected is not easy to happen.Large peaks or valleys will be observed in the magnetic memory signals at the area of segregation,which supply a new method for identifying segregation of ferromagnetic materials.