研究了50W540型无取向硅钢中MnS粒子在300~700℃时效处理0.75~24 h不同时间时效析出行为与铁损变化的关系。结果表明,α-Fe基体中过饱和的Mn、S原子以MnS粒子形式沿位错析出,Mn原子的扩散距离是析出行为的制约因素。700℃时效时过饱和度低、Mn扩散快而MnS粒子易粗化,铁损降低。400~600℃时效时过饱和度高、MnS粒子析出数量增多,铁损升高。400℃以下时效时过饱和度很高,但Mn扩散慢,使细小MnS粒子难以析出且铁损无明显变化。 The relationship between precipitation behavior and iron loss of MnS particles in 50W540 non-oriented silicon steel at 300 ~ 700 ℃ aging at 0.75 ~ 24 h was studied. The results show that the supersaturated Mn and S atoms in α-Fe matrix dislocate along the dislocations in the form of MnS particles, and the diffusion distance of Mn atoms is the limiting factor of the precipitation behavior. When aging at 700 ℃, the supersaturation is low, Mn diffuses quickly and MnS particles tend to roughen and iron loss decreases. 400 ~ 600 ℃ aging high saturation, MnS particles precipitation increased, iron loss increased. Below 400 ℃, the supersaturation is very high under aging, but the diffusion of Mn is slow, which makes it difficult for fine MnS particles to precipitate and no obvious change of iron loss.