孕育处理对可锻铸铁低温石墨化能力的影响

Effect of inoculation treatment on the low temperature graphitization of malleable cast iron

考察了不同的孕育剂对可锻铸铁低温石墨化的影响 .通过研究发现可锻铸铁所用的孕育剂中有Si Fe存在 ,在 750℃～ 730℃左右、保温时间少于 2 7小时退火时 ,就能得到全铁素体基体的可锻铸铁 .在一般的砂型铸造过程中 ,以Si Fe Bi Al复合孕育效果最好 .扫描电镜分析表明 ,加Si Fe孕育后 ,由于Si分布的不均匀使得可锻铸铁的低温石墨化过程易于实现 .

Several kinds of inoculation influencing the graphitization of malleable at low temperature have been examined. It is demonstrated that all ferrite matrix malleable cast iron can be got from white cast iron by annealing within 27 hours at the isothermal preservation temperature of 750℃～730℃ when the melting iron is complexly inoculated by Si Fe and Bi Al. In the process of common sand model casting, the effect of complex inoculation with Si Fe Bi Al is best. SEM analysis shows that after inoculater Si Fe is added, the distribution of Si is heterogeneous which makes low temperature graphitization of the malleable cast iron easy.