摘要
对含Hf和Ta新型镍基高温合金FGH98Ⅰ等离子旋转电极(PREP)雾化原始和不同温度下预热处理粉末中的碳化物相进行了研究.结果表明:原始粉末中MC′型碳化物可分为两类,一类为富Ti、Ta和Nb,另一类为含Ta、Hf和Zr.两类碳化物均含有一定量非碳化物形成元素Co和Ni及中等强碳化物形成元素Cr和Mo,并以块状、粒状分布于枝晶或胞晶间;随着预热处理温度升高,粉末中富Ti、Ta和Nb的MC′型碳化物转变为MC型碳化物,且其所含Ti、Ta和Nb的总量增大;含Ta、Hf和Zr的MC′型碳化物发生分解和转变,析出稳定的M23C6、M6C和MC型碳化物,M23C6碳化物的析出和溶解温度为950℃和1150℃,M23C6和M6C碳化物共存温度为1000～1100℃.另外,粉末中微量元素Hf和Ta主要以碳化物和γ′相参与碳化物反应.
Carbides in new type Hf-Ta-containing nickel-based superalloy FGH98 Ⅰ powders prepared by plasma rotating electrode processing（PREP）before and after pre-heat treatment at different temperatures were studied.The results show that MC＇ type carbides in the initial powders can be divided into two groups.One is rich in Ti,Ta,Nb and the other contains the elements of Ta,Hf and Zr.The two types of carbides both contain a certain amount of non-carbide forming elements（Co,Ni）and medium carbide forming elements（Cr,Mo）,and these carbides locate between interdendrites or cells and in block and granule shapes.Ti-Ta-Nb riched MC＇ type carbides in the powders can be transformed into MC type carbides and the total amount of Ti-Ta-Nb increases with increasing pre-heat treatment temperature.The Ta-Hf-Zr contained MC＇ type carbides can be decomposed and transformed into M23C6,M6C and MC type carbides.It is also shown that the precipitate and dissolution temperatures of M23C6 type carbides are 950℃ and 1150℃ respectively,and the co-existing temperature of M23C6 and M6C type carbide is within the range from 1000℃ to 1100℃.In addition,trance elements Hf and Ta in the powders take part in the reactions of carbides mainly in the form of carbides and γ＇ phases.
出处
《北京科技大学学报》
EI
CAS
CSCD
北大核心
2010年第11期1464-1470,共7页
Journal of University of Science and Technology Beijing
基金
国家预研基金资助项目(No.9140A12070507QT0202)
国家高技术研究发展计划资助项目(No.2007AA03A223)
