热处理对NbVTi合金灰铸铁组织和性能的影响  

Effect of heat treatment process on microstructure and properties of NbVTi alloyed gray iron

作　　者：王娜娜[1] 刘金祥[1] 熊毅[2] 

机构地区：[1]北京理工大学机械与车辆学院,北京100081 [2]河南科技大学材料科学与工程学院,河南洛阳471000

出　　处：《材料热处理学报》2015年第2期114-118,共5页Transactions of Materials and Heat Treatment

基　　金：国家"973"计划资助项目(52234703)

摘　　要：借助扫描电子显微镜(SEM)和力学性能测试手段,研究了新型贝氏体基体Nb VTi合金灰铸铁经过不同保温时间和温度的热处理后微观组织和力学性能的变化。结果表明:随着保温时间的增长或温度的升高,Nb VTi合金灰铸铁的贝氏体基体组织发生粗化,A型片状石墨厚度和长度增大;拉伸断口呈现准解理断裂特征,并随保温时间或温度的增加出现了一定程度的韧性断裂特征,塑韧性得到改善;随保温时间或温度的增加,Nb VTi合金灰铸铁的抗拉强度和布氏硬度呈下降趋势。Microstructure and mechanical properties of newly developed Nb VTi alloyed gray iron after heat treated at different temperatures for different time,were studied by means of scanning electron microscopy( SEM) and mechanical property tests. The results show that with the increase of holding time or temperature,cicular bainite becomes thicker and shorter,meanwhile,graphite gets thicker and longer. The tensile fracture of Nb VTi alloyed gray iron is quasi-cleavage fracture. Ductile rupture characteristics appear on the fracture which lead to improvement of the alloy's plasticity and toughness. The tensile strength and Brinell hardness of Nb VTi alloyed gray iron decrease with the increase of holding time or temperature.

关 键 词：NbVTi合金灰铸铁 热处理 微观组织 力学性能 

分 类 号：TG163[金属学及工艺—热处理] TG143.2[金属学及工艺—金属学]