镍基粉末高温合金枝晶间亚稳碳化物  

Non-equilibrium carbides in the interdendritic region of a nickelbased powder metallurgy superalloy

作　　者：马文斌[1] 刘国权[1,2] 胡本芙[1] 吴凯[1] 张义文[3] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]北京科技大学新金属材料国家重点实验室,北京100083 [3]钢铁研究总院高温材料研究所,北京100081

出　　处：《北京科技大学学报》2013年第6期770-776,共7页Journal of University of Science and Technology Beijing

基　　金：国家重点基础研究发展计划资助项目(2010CB631204)

摘　　要：对急冷凝固镍基高温合金松散粉末热等静压成型合金中亚稳碳化物及其相间反应进行了研究.随着热处理温度的升高,粉末中合金元素的分布逐渐均匀化,但枝晶间MC能在较高的温度下保持稳定,使Ti和Zr在该处仍有较高含量.原始粉末中枝晶间主要分布着块状和花状的MC型碳化物,在预热处理过程中粉末枝晶间块状碳化物分解,发生M23C6和M6C的析出反应,而花状碳化物的成分及形貌则保持相对稳定.成型合金残余枝晶间分布的碳化物主要由块状M6C和MC及花状MC组成,形变再结晶可以促进枝晶间碳化物的溶解.This article studies carbides and their reactions in nickel-base superalloy powders prepared by rapid solidification and the hot isostatic pressed （HIPed） alloy. With the pre-treated temperature rising, the segregation of alloy elements in the powders reduces, but MC carbides in the interdendritic region still exist at elevated temperatures. As a result, there are more Ti and Zr at this area. Blocky and petal-like MC carbides distribute in the interdendritic region of the initial powders. During the pre-heat treatment the blocky carbides decompose, and M23C6 and M6C precipitate in the interdendritic region; however, the petal-like carbides can remain stable at higher temperatures. Carbides in the interdendritic region of the HIPed alloy are composed of blocky M6C and MC and petal-like MC carbides, but deformation and recrystallization can induce the MC carbides to decompose.

关 键 词：高温合金 镍合金 粉末冶金 热等静压 枝晶 偏析 碳化物 预热处理 

分 类 号：TG146.15[一般工业技术—材料科学与工程] TF124.32[金属学及工艺—金属材料]