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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.
The results show that the carbides of MC ’type carbides can be divided into two kinds: the first type and the second type, which are composed of Hf and Ta, a new type of nickel-based superalloy FGH98Ⅰ plasma rotating electrode (PREP) atomized at different initial and different temperatures. Two types, one is rich in Ti, Ta and Nb, and the other is Ta, Hf and Zr.The two types of carbides contain a certain amount of non-carbide forming elements Co and Ni and medium carbide forming elements Cr and Mo, and distributed in dendrites or intergranular in the form of lumps; with increasing preheating temperature, the MC ’carbide rich in Ti, Ta and Nb in the powder is transformed into MC type carbides and the The total amount of Ti, Ta and Nb increases; the MC ’carbide containing Ta, Hf and Zr decomposes and changes, and stable M23C6, M6C and MC carbides are precipitated and the precipitation and dissolution temperature of M23C6 carbide is 950 ℃ and 1150 ℃, the coexistence temperature of M23C6 and M6C carbides is 1000 ~ 1100 ℃ .In addition, the trace elements Hf and Ta in the powder mainly participate in carbide reaction with carbides and γ ’phases.