冷却速度对离心铸造高硼高速钢辊环组织的影响  

Effect of cooling rate on microstructure of high boron high speed steel roll ring produced by centrifugal casting

作　　者：蒋一[1] 岑启宏[1] 蒋业华[1] 周荣[1,2] 

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093 [2]云南省先进成形制造工程技术研究中心,云南昆明650093

出　　处：《材料热处理学报》2013年第4期128-132,共5页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51171073);云南省院省校科技合作专项(2010AD012);云铜校企基金(KKZ4201151003);昆明理工大学分析测试基金(2011004)

摘　　要：采用空冷和水冷不同铸型方式,研究冷却速度对离心铸造高硼高速钢辊环组织的影响,制备出辊环。结果表明:铸态高硼高速钢辊环组织由树枝状基体和硼碳化物组成。快速冷却下,基体组织全部转化为马氏体;硼碳化物的类型没有发生变化,由M2(B,C)、M3(B,C)以及M23(B,C)6组成。随着冷却速率的增加,基体晶粒尺寸减小,硼碳化物数量减少,鱼骨状硼碳化物向筛网状转变,局部出现缩颈和孤立现象。冷却速度的增加影响了合金元素在基体和硬质相中的分布,硬质相的显微硬度不变,基体硬度略有增加。空冷砂型离心铸造时,随着距辊环外边缘距离的增加,出现菊花片状的包晶组织,并且数量也逐渐增加。In order to study the effect of cooling rate on microstructure of high boron high speed steel roll ring produced by centrifugal casting, roll rings were produced through air cooling and water cooling using different moulds. The results show that the as-cast microstructure of high boron high speed steel roll ring consists of dendritic matrix and borocarbides. In rapid cooling condition, the microstructure is composed of martensite matrix and borocarbides of M2 （ B, C） , M3 （ B, C ） and M23 （ B, C ） 6. As increasing the cooling rate, the grain size of matrix is decreased, the number of carboborides is reduced, the carboborides are changed from fishbone form to cribriform shape, and local necking and grain refinement is observed. Increasing cooling rate changes the distribution of alloy elements in matrix and hard phase. Microhardness of matrix increases slightly and microhardness of the hard phase remains un-changed as inoreasing the cooling rate. When roll ring is produced through air cooling for sand mould, chrysanthemum-shaped peritectic structure appears and its amount increases with increasing distance from outside edge of the roll ring.

关 键 词：冷却速度 离心铸造 高硼高速钢 组织 

分 类 号：TG249.4[金属学及工艺—铸造]