(1. 西安理工大学 材料科学与工程学院, 西安 710048；
2. 北京航空材料研究院, 北京 100095)
摘 要: 采用等温凝固实验与差热分析相结合的方法, 对无Ru和含3.0%（质量分数）Ru的两种低Cr高W铸造镍基高温合金的凝固过程进行了比较分析， 得到两种合金在不同温度下的凝固组织、凝固顺序图和凝固特性曲线。 结果显示：Ru的加入对低Cr高W铸造镍基高温合金的液相线温度无明显影响， 但对初生MC碳化物以及γ+γ′共晶的析出温度有明显作用。 Ru是一个偏析倾向很弱的元素， 且不改变其他合金元素的偏析特性。 加Ru可以起稳定γ的作用， 能有效抑制大块初生M6C碳化物的形成。 显示了Ru对低Cr高W铸造镍基高温合金显微组织稳定性的有利作用。
关键字: 镍基高温合金; Ru; 差热分析; 等温凝固
（1. School of Materials Science and Engineering, Xi′an University of Technology,Xi′an 710048, China;
2. Institute of Aeronautical Materials,Beijing 100095, China）
Abstract:The solidification process of two kinds of cast nickel base superalloys with low content of Cr and high content of W, in which 3%（mass fraction）Ru was added or was not contained, was comparatively studied by the method of DTA and isothermal solidification experiment. The solidified structure at different temperature, solidification sequence and solidification characteristic diagram were obtained. The results show that the addition of Ru into the cast nickel base superalloy with low content of Cr and high content of W does not affect liquidus temperature of alloy, but can influence the precipitation temperature of primary MC carbide and eutectic γ+γ′ obviously. Ru is a very weak segregation element and does not change the segregation characteristic of other alloying elements. Ru isγstabilizer and can restrict the formation of large block shaped M6C carbide effectively. Therefore Ru is considered as a beneficial alloying element for stabilizing microstructure of cast nickel base superalloys with low content Cr and high content W.
Key words: nickel base superalloy; Ru; DTA; isothermal solidification
