两种连铸环套内孔磨损失效的原因分析  

Cause Analysis of Wear Failure of Inner Hole of Two Kinds of Continuous Casting Ring Sleeve

作　　者：许旸[1,2] 王海生[1] 颜国君[1] 白柯 

机构地区：[1]西安理工大学材料科学与工程学院,陕西西安710048 [2]陕西同心连铸管业科技有限公司,陕西咸阳713300

出　　处：《热加工工艺》2017年第5期254-256,共3页Hot Working Technology

基　　金：陕西省教育厅产业化培育项目(2010JC13);陕西省自然科学基金项目(2015JM5217)

摘　　要：水平连铸棒材的横截面中存在一个由液芯区转变而成的圆形区域。由于冷却中热量传输不对称和成分偏析的原因,这个区域中的石墨为A、B型且尺寸粗大,淬硬性元素含量低于先行冷凝壳层中的含量,导致硬度偏低。另一方面,由于地心引力的存在,结晶器石墨套与冷凝壳层间的上部有一个月牙形的气隙,严重阻碍了壳层中热量向上方的传输,最终造成了液芯区在横截面上的偏心分布。在随后的冷加工钻削中,若环套的壁较厚,这个液芯区往往不能全部切削掉,而是留下了一个月牙形的液芯区,致使环套在该位置首先磨损。用垂直连铸方法拉制空心型材,避免了地心引力的干扰从而消除了月牙形气隙,型材横断面中没有了液芯区,所获得的铸态组织细密,硬度均匀,内孔耐磨性一致。There is a circular region transformed from a liquid core in cross section of bar produced by horizontal continuous casting. Due to the unbalanced heat transmission and composition segregation during cooling, the graphite in the region is type A, B, whose size is large, and the contents of hardening elements are lower than those of early solidified shell, thus its hardness is lower. On the other hand, due to the gravity, there is a crescent shaped air gap between crystallizer graphite sleeve and solidified shell, which seriously hinders the transfer of heat to the top of the shell and causes the eccentric distribution of the liquid core zone in the cross section. In the subsequent drilling process, if the ring sleeve wall is thick, the liquid core area can＇t be completely cut off, and it leads to the wear of this location firstly. However, when the sleeve is made of hollow bar produced by vertical continuous casting, its microstructure is fine and compact and the inner hole has uniform hardness and wear resistance of due to the elimination of crescent shaped air gap, the disappearance of liquid core.

关 键 词：环套 水平连铸 垂直连铸 铸铁型材 谐波减速器 活塞环 

分 类 号：TG250[金属学及工艺—铸造]