一、绪言曾出现过各种利用钢材磁性质变化的无损试验方法。对强磁性材料加外磁场磁化时,由于磁化过程中磁畴位移不连续,使得磁化过程不连续。这种现象很早就被人们所了解。称之为巴克豪森效应。曾有人提出磁畴的大小同晶体粒度有密切关系,根据巴克豪森效应能测量晶体的粒度。此外,还提出巴克豪森效应对应力非常敏感,利用这种性质能预测材料疲劳破坏的程度。 AE法作为无损探伤的新方法,正有效地活跃在各个领域。强磁性材料磁化过程的 I. INTRODUCTION There have been various nondestructive testing methods that make use of changes in the magnetic properties of steel. When the external magnetic field magnetization is applied to the ferromagnetic material, the magnetization process is discontinuous due to the discontinuous displacement of the magnetic domains during magnetization. This phenomenon has long been known to people. Call it the Barkhausen effect. It has been suggested that the size of the magnetic domain is closely related to the size of the crystal, according to the Barkhausen effect can measure the crystal size. In addition, it is also suggested that the Barkhausen effect is very sensitive to stress, and the use of this property can predict the degree of material fatigue failure. AE method as a new method of non-destructive testing, is effectively active in various fields. Ferromagnetic material magnetization process