(1. 西安理工大學(xué) 材料科學(xué)與工程學(xué)院, 西安 710048；
2. 北京航空材料研究院, 北京 100095)
摘 要: 采用等溫凝固實(shí)驗(yàn)與差熱分析相結(jié)合的方法, 對無Ru和含3.0%（質(zhì)量分?jǐn)?shù)）Ru的兩種低Cr高W鑄造鎳基高溫合金的凝固過程進(jìn)行了比較分析， 得到兩種合金在不同溫度下的凝固組織、凝固順序圖和凝固特性曲線。 結(jié)果顯示：Ru的加入對低Cr高W鑄造鎳基高溫合金的液相線溫度無明顯影響， 但對初生MC碳化物以及γ+γ′共晶的析出溫度有明顯作用。 Ru是一個(gè)偏析傾向很弱的元素， 且不改變其他合金元素的偏析特性。 加Ru可以起穩(wěn)定γ的作用， 能有效抑制大塊初生M6C碳化物的形成。 顯示了Ru對低Cr高W鑄造鎳基高溫合金顯微組織穩(wěn)定性的有利作用。
關(guān)鍵字: 鎳基高溫合金; Ru; 差熱分析; 等溫凝固
（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
