强化高碳当量灰铸铁组织初探

An Exporatory Investigation on Strengtheningthe Microstructure of Gray Cast Iron With High CE

对高碳当量铁水、应用Ti、Mn复合添加,利用Ti细化石墨,增加组织中奥氏体枝晶数量、细化奥氏体枝晶及影响奥氏体枝晶分布的作用和Mn消除基体中铁素体的作用,有效地克服了高碳当量灰铸铁石墨易粗大,奥氏体枝晶数量少及基体中易产生铁素体等不利因素的影响,使其强度有较大的提高.在实验条件下,碳当量4.0~4.2%时,组织为D型石墨、20%以上奥氏体枝晶和珠光体加索氏体基体的灰铸铁,强度均在HT300牌号以上.

In this paper the comprehesive effects of Ti and Mn on the miitrostructure of gray cast iron with high CE were studied.The element Ti fines the size of graphite and aus-tenite dendrites, increases the quantity of austenite dendrites and improves its distribution.The element Mn can eliminate the undesirable effects of ferrite in matrix, preventco-arsenness of graphite size and reduction of austenite dendrites in gray cast iron with high CE,therefore,the strength is greatly increased.The experimental results showed that D-type graphite more than 20% austenite dendrites and pearlite-troostite matrix in gray cast iron with 4.0-4.2% CE were obtained the strength is higher than HT300.