Fe-Cr-C过共晶原位生长复合材料定向凝固的研究  

Study of Fe-Cr-C Hypereutectic Alloy Formed In-situ under Unidirectional Solidification

作　　者：李浩[1] 严文[1] 陈建[1] 牛艳娥[2] 范新会[2] 

机构地区：[1]西北工业大学应用物理系,陕西西安710072 [2]西安工业大学材料与化工学院,陕西西安710032

出　　处：《铸造技术》2007年第3期307-311,共5页Foundry Technology

基　　金：陕西省教育厅科研专项(06JK276);教育部优秀青年教师奖励计划资助项目

摘　　要：采用液态金属冷却的定向凝固设备,研究了过共晶高铬铸铁(2.96%C-27.22%Cr)原位生长复合材料的定向凝固组织和性能。结果表明,初生碳化物和共晶碳化物均为M7C3型碳化物;初生碳化物以包抄方式生长,逐渐形成闭合六边形环状;随着凝固速度的增加,初生碳化物的大小和体积分数均减小;初生碳化物横截面的显微硬度为2 000 HV左右,纵截面为1 450 HV左右;随着凝固速度的增加,抗拉强度呈马鞍型变化,当凝固速度为15μm/s时,抗拉强度最大,可达1 913 MPa。The unidirectional solidified structure and mechanical properties of in situ formed Fe-Cr-C hypereutectic alloy （2.96 %C-27.22 %Cr） have been studied by unidirectional solidification appartus with liquid metal cooling The results show that primary carbides and eutectic carbides are M7C3-type carbides; primary carbides grow in the manner of outflanking and the transverse section of primary carbides is hexagonal; with the increase of solidification rate, the size and volume fraction of primary carbides will decrease; the micro-hardness of transverse section of primary carbides is about HV 2 000, while the hardness of longitudinal section of primary Carbides is about HV 1 550. With the increase of solidification rate, the tensile strength of Fe-Cr-C hypereutectic alloy decreases first, then increases and finally drops sharply. The maximum tensile strength can reach up to 1 913 MPa when the solidification rate is 15 μm/s.

关 键 词：定向凝固 凝固速度 初生碳化物 共晶碳化物 

分 类 号：TB331[一般工业技术—材料科学与工程]