一种铸造镍基高温合金的凝固行为  

SOLIDIFICATION BEHAVIOR OF A CAST NICKEL-BASE SUPERALLOY

作　　者：孙晓峰[1] 殷凤仕[1] 李金国[1] 侯贵臣[1] 郑启[1] 管恒荣[1] 胡壮麒[1] 

机构地区：[1]中国科学院金属研究所,沈阳110016

出　　处：《金属学报》2003年第1期27-29,共3页Acta Metallurgica Sinica

摘　　要：M963合金的凝固顺序为: L→L+γ→L+(γ＇+MC)+γ→(γ+γ＇)+(γ+MC)+γ→(γ+γ＇)+(γ+MC)+γ+γ＇;凝固组织呈树枝状结构,由γ固溶体基体、γ＇析出相及分布在枝晶间区的骨架状MC碳化物和(γ+γ＇)共晶组成;碳降低合金的液相线温度和(γ+γ＇)共晶温度,提高MC碳化物的形成温度,增加MC碳化物的体积分数,降低(γ+γ＇)共晶的体积分数;高熔点元素W和Co在枝晶干偏聚, Al,Ti,Nb,Cr和Mo在枝晶间偏聚.The solidification behavior and as-cast microstructure feature of a cast nickel-base superalloy M963 have been investigated by SEM (EDXS) and DTA. The results show that the solidification sequence of M963 superalloy is as follows: L-->L+gamma --> L+(gamma'+MC)+ gamma --> (gamma+gamma') + (gamma+MC)gamma --> (gamma + gamma') + (gamma + MC)+gamma + gamma'. The as-cast microstructure is dendritic and consists of gamma solid solution matrix, gamma' precipitate, the script-like MC carbide and (gamma + gamma') eutectic in the interdendritic region. Carbon causes a decrease in liquidus and (gamma + gamma') eutectic temperature, and an increase in MC carbide formation temperature, thus decreases the volume fraction of (gamma + gamma') eutectic and increases the volume fraction of MC carbide. The refractory element W and Co are rich in dendrite arm but Al, Ti, Nb, Cr and Mo rich in interdendritic region.

关 键 词：铸造镍基高温合金 凝固 显微组织 差热分析 

分 类 号：TG146.15[一般工业技术—材料科学与工程] TG111.4[金属学及工艺—金属材料]