衔铁材料1J50磨削后抛光与去应力处理对断路器吸合性能的影响

Influence of Polishing and Stress Relief of Armature Material 1J50 after Grinding on Pull-in Performance of Circuit Breakers

衔铁的磁性能和表面平整度对断路器的吸合电流有很大的影响。利用氢气保护磁性退火热处理后,衔铁的磁性能提高,但还需要进行磨削加工以保证材料表面的平整度。而经砂轮磨削后,会带来表面冷变形,使其磁性能下降。为了克服磨削后带来的磁性能下降问题,以坡莫合金1J50作为衔铁材料,分别采用回火去应力以及抛光工艺进行后处理,对比两种方案下衔铁材料的磁性能变化情况。试验数据表明:坡莫合金1J50经过氢气保护热处理后,晶粒尺寸变大,磁性能改善;经磨削冷变形后,磁性能有所下降,这是由其表面产生很大的内应力导致的;对比采用回火去应力热处理以及抛光对衔铁磁性能的改善效果,可以看出,去回火去应力热处理优于抛光处理。

The magnetic properties and surface flatness of armature have great influence on the pull-in current of circuit breaker.However,grinding is needed to ensure the smoothness of the material surface.After grinding,the surface will be cold deformed and the magnetic properties will be decreased.In this paper,permalloy 1J50 is used as the armature material.In order to overcome the problem of magnetic properties decline after grinding,temper stress relief and polishing processes are used respectively for post-treatment.The magnetic properties of the armature material under the two schemes are compared.The experimental data show that the grain size of permalloy 1J50 increases and the magnetic properties improve after hydrogen protective heat treatment.After cold deformation,the magnetic properties decrease,which is due to the internal stress on the surface.By comparing the effect of tempering and polishing on the magnetic properties of armature,it can be seen that temper stress relief and polishing is better than polishing.