感应电炉生产灰铸铁缸体、缸盖的技术探讨

Discussion on Induction Furnace Melting Technique of Gray Iron Used for Cylinder Block and Head Casting

对感应电炉熔炼灰铸铁过程中废钢的选用、Si C的使用、铁液过热和高温静置、出炉孕育、随流孕育及出炉补C工艺等问题进行了探讨,总结出以下结论：（1）加入一定量的Si C作为预处理剂,可增加铁液中的形核核心,降低白口倾向,还可减少铁液中的氧化渣;（2）生产合成铸铁时,需选用经过高温石墨化的增碳剂,并对废钢的来源进行严格管控,可通过选用Si-Zr孕育剂消除N2气孔;（3）铁液的过热温度控制在1 500~1 530℃,过热时间为5~10 min最佳;（4）出炉补C工艺,不仅能稳定炉后C成分,还起到一定的孕育作用,增加铁液石墨核心,降低白口倾向。

An discussion was conducted on the problems during the induction furnace melting gray iron process with steel scrap choice,usage of Si C,iron melt superheating and high temperature holding,tapping inoculation,tapping recarburation process et al.,and the following conclusions were summarized：（1）Adding proper amount of Si C as pre-treating agent could increase the nucleus to promote the iron melt nucleation and reduce chilling tendency,and could also reduce the oxide slag in iron melt.（2）When producing synthetic cast iron,it was necessary to use the recarburizer which had been graphitized at high temperature and strictly control the resource of the steel scraps;it was possible to use Si-Zr inoculant to eliminate nitrogen fissures.（3）The superheating temperature of iron melt was controlled in the range of 1 500~1 530 ℃,the best superheating duration was of 5~10min.（4）Tapping recarburation process could not only to stabilize the final carbon content,and also have in some degree inoculating effect to increase the graphite nucleus of iron melt and reduce chilling tendency.