轴向应力对铁磁材料磁极性影响研究

为研究外加应力作用下铁磁材料磁极性变化规律，制作Q235钢轴状静载拉伸试件，在MTS810型液压伺服试验机上进行正向或反向多级加载，采用EMS2003金属磁记忆仪检测拉伸过程试件表面磁记忆信号变化，分析加载顺序、加载次数及应力大小对磁极性影响。研究结果表明：同一加载方向上试件磁极性不变，加载应力大小决定磁极性强弱，正反方向加载试件产生相反的磁极性。同一加载方向、同一加载应力条件下，加载次数不影响磁极性；改变加载方向，加载应力需逆转磁畴结构取向，加载次数增多使磁极性略有增强。

Influence of Axial Stress on Magnetic Polarity of Ferromagnetic Materials

In order to clarify the change law of magnetic polarity of ferromagnetic materials under the effect of applied stress, Q235 steel sheet specimens are used to perform several forward or backward load- on by means of an MTS810 hydraulic servo testing machine. An EMS2003 metal magnetic memory apparatus is used to collect the magnetic signals on the surface of specimens during tensile processes and the influence of loading direction, frequency and stress magnitude on the magnetic polarity of specimens is analyzed. The results show that the magnetic polarity of specimen is invariant under the same loading direction, the applied stress amplitude determines the magnetic polarity strength and the forward or backward loading induces opposite magnetic polarity. The loading frequency affects hardly the magnetic polari- ty of specimens under the same loading direction and stress amplitude. If loading direction changes, loading frequency strengthens the magnetic polarity of specimen lightly because loading stress reverses the orientation of magnetic domain.