消应力退火对无取向硅钢组织和磁性能的影响

采用连续退火和井式退火两种消应力退火工艺生产35SW440牌号的爱泼斯坦方圈样，并对不同消应力退火工艺与组织、析出及磁性能之间的关系进行了比较研究。结果表明：一次退火板经消应力退火后铁损明显降低，磁感增加。与井式退火工艺相比，连续退火工艺生产的铁心在高磁密条件下磁性能较差，主要原因是带钢表面出现了明显的表面渗氮现象。表面渗氮源于其保护气氛、退火工艺设计不合理，形成大量细小弥散的AlN析出物。AlN析出物通过影响磁畴壁和磁矩运动，恶化磁性能。井式退火工艺由于有效控制了带钢表面渗氮，显著降低了电工钢片高磁密下铁损值，使成品铁心性能指标得到改善。

Effect of stress relieving annealing process on microstructure and magnetic properties of non oriented silicon steel

Epstein frame samples of the silicon steel of 35SW440 were produced by two stress relieving annealing processes of continuous annealing and well annealing. The comparative investigations were conducted on the relationships between the two stress relieving annealing process and their microstructures, precipitation and magnetic properties. The results showed that after stress relief annealing, the iron loss reduced and the magnetic induction improved. Compared with the well type annealing process, the iron core of the steel produced by continuous annealing process had poor magnetic properties under the condition of high magnetic density due to the obvious surface nitriding phenomenon on the surface of the steel. The surface nitriding was due to the unreasonable design of the protective atmosphere and annealing process, resulting in a large number of fine and dispersed AlN precipitates produced in steel. AlN precipitates affected the movement of domain wall and magnetic moment, resulting in the deterioration of magnetic properties. By contrast, the well annealing process reduced the iron loss of the electrical steel sheet under high magnetic density, and improved properties index of iron core due to the effective control of the surface nitriding in steel.