磁记忆检测技术是近期发展起来的可早期发现金属检测试件损伤的新的无损检测方法, 研究磁化反转效应可以解决磁记忆检测技术中的基础问题和应用瓶颈。通过反复地加载和卸载, 测量了Q235低碳钢试件在不同的扭矩作用下, 表面固定点磁感应强度随扭矩变化的对应关系。试验结果表明, 在弹性阶段, 磁感应强度B与扭矩T近似成直线关系。当扭矩T达到或超过屈服扭矩（39.98 N·m）之后, 磁感应强度B与扭矩T的关系表现为先增大后减小。随着屈服过程向圆心的转移, 磁感应强度差值ΔB的差距进一步加大。在接近抗拉扭矩后, 磁感应强度差值ΔB的变化量进一步增大。试验得出: 试件的磁感应强度在扭矩作用下, 存在磁化反转效应, 并对扭转过程中的力-磁关系做出了简单的评价。

The metal magnetic memory technology is a recently developed new NDT method capable of the early detection of damages in test piece. Study on the magnetization reversal effect is to understand the basic principle of magnetic memory testing technology and to solve its application bottlenecks. By repeatedly loading-unloading the Q235 mild steel specimens under different torques, the magnetization value at surface fixed point was measured together with corresponding torques. The results show that at the elastic stage the magnetic flux density B shows approximately linear relationship with torque T. When the torque T reaches or exceeds the yield torque (39.98 N·m), the relationship between them performs as increasing first and then decreasing. With the yield process transferring to the center, the gap magnetic flux density ΔB is further opened. After approaching the tensile torque, the amount of change in magnetic flux density ΔB is further increased. Test shows that there exists the magnetizing reversion effect in the specimen magnetic flux density under the effect of torque, and it may provide basis for the evaluation of the stress-magnetism relationship in the course of torsion action.