瞬时孕育剂的粒度分布对球铁显微组织的影响

Influence of Grain Size Distribution of Instantaneous Inoculant on Microstructure of Nodular Iron

采用自动瞬时孕育装置对球墨铸铁进行瞬时孕育处理,在控制化学成分、浇注温度、球化剂和瞬时孕育剂加入量基本相同的情况下,研究了瞬时孕育剂粒度分布对球墨铸铁显微组织的影响。结果表明,瞬时孕育剂粒度分布影响其在铁液中单位时间内的熔化量,随大颗粒含量的逐渐减少,球化率等级先提高后降低,基体组织中珠光体体积分数随大颗粒含量减少而有所降低。试验发现,在各组瞬时孕育剂中,粒度分布为40目的占45%,50目的占30%,70目的占20%,大于70目的占5%时,孕育效果最佳。

By using automatic instantaneous inoculation device to conduct instantaneous inoculation of nodular iron and by controlling the chemical composition,pouring temperature,as well as the addition amount of nodularizing alloy and the addition amount of instantaneous inoculant basically the same,the influence of grain size distribution of instantaneous inoculant on the microstructure of nodular iron was investigated. The result showed that the distribution of the instantaneous inoculant influenced its dissolution amount in iron melt per unit time,therefore,with gradual reducing of big size gain content,the nodularity grade first was elevated and then decreased,the pearlite volume fraction was some decreased with the big grain content reducing. It was found that, among all size distribution groups ,the best inculation effect was obtained by group containing 45% of 40 mesh, 30% of 50 mesh, 20% of 70 mesh and 5% of 〉70 mesh.