铁液预处理在球墨铸铁和灰铸铁生产中的应用

分析了感应电炉熔炼铁液石墨结晶核心减少的原因,说明石墨结晶核心减少会增大灰铸铁和球墨铸铁件的缩孔、缩松倾向,降低铸件的力学性能。指出预处理的主要作用是增加铁液的石墨结晶核心,改善球化处理和孕育处理的效果。叙述了常见预处理剂的特点,详细介绍了SiC预处理的具体操作要点,主要是:炉内铁液成分和温度合适时,扒渣,加入预处理剂,升温至工艺要求温度,尽快出炉和浇注。最后,比较了球墨铸铁和灰铸铁采用预处理前后的石墨形态,指出正确使用预处理对提高球墨铸铁和灰铸铁件的质量起着非常重要的作用。

Application of Iron Liquid Pretreatment in Nodular Iron and Gray Iron Production

The application of iron melt pretreatment in induction furnace-produced nodular iron and gray iron was described.The followings were explained in detail,the reason causing graphite crystallization nuclei number reducing when using induction furnace melting.The graphite crystallization nuclei number reducing may cause graphite number reducing and increase shrinkage tendency and decrease mechanical properties of nodular and gray irons.The main effect of pretreatment was to increase graphite crystallization nuclei number of iron melt and improve the effect of nodularization and inoculation.There were many kinds of materials that could be used as pretreatment agents,and in actual production,several materials were often together used and would bring better effect.The main operating points of SiC pretreatment were:when the composition and temperature of iron melt in the furnace are appropriate,the slag was skimmed off,add the pretreatment agent,raise the inner-furnace temperature to the process-required temperature,quickly tap the melt and pour the melt as soon as possible.