(1. 北京科技大學(xué) 冶金與生態(tài)工程學(xué)院，北京 100083；
2. 鋼鐵研究總院 高溫材料研究所，北京 100081)
摘 要: 基于Thermo-Calc熱力學(xué)計(jì)算軟件及相應(yīng)的Ni基數(shù)據(jù)庫，對(duì)FGH96高溫合金中一次碳化物的生成機(jī)理進(jìn)行研究，計(jì)算FGH96高溫合金可能的平衡析出相及C、N、Nb、Ti元素對(duì)合金中一次碳化物相MC+M(C,N)析出行為的影響，對(duì)比分析FGH96高溫合金中一次碳化物相的計(jì)算結(jié)果與掃描電鏡圖及能譜分析的化學(xué)成分。結(jié)果表明：C含量對(duì)一次碳化物相的析出量影響較大，而對(duì)析出溫度影響較小；N含量對(duì)析出溫度有非常明顯的影響，而對(duì)一次碳化物相的析出量影響較小；Nb和Ti含量對(duì)FGH96高溫合金中一次碳化物相的析出行為只有輕微的影響。因此，F(xiàn)GH96高溫合金中一次碳化物相的析出行為主要受C和N的影響。由計(jì)算得出的一次碳化物相的成分變化結(jié)果結(jié)合掃描電鏡圖和能譜分析結(jié)果可推斷出，F(xiàn)GH96高溫合金中含有N時(shí)，首先從液態(tài)合金中析出含有微量C的氮化物TiN，兩相區(qū)析出的MC型碳化物會(huì)在TiN表面析出，形成以TiN為核心的一次碳氮化物M(C,N)。
關(guān)鍵字: FGH96高溫合金；一次碳化物；碳氮化物；熱力學(xué)計(jì)算
（1. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China;
2. Department of High Temperature Materials, Central Iron and Steel Research Institute, Beijing 100081, China）
Abstract:The formation mechanism of primary carbides in FGH96 superalloy was investigated based on the Thermo- Calc thermodynamic software combined with the related nickel-based database. Using Thermo-Calc thermodynamic software, the possible equilibrium precipitation phases were calculated, and the effects of C, N, Nb and Ti elements on the precipitation behaviors of the primary carbide phase MC+M(C,N) were investigated. The calculated results of the primary carbide phase in FGH96 superalloy were compared with scanning electric microscope (SEM) image as well as measured chemical composition by energy dispersive spectrometer (EDS) of the FGH96 superalloy samples. The results show that the C content has a large effect on the mass fraction of the precipitated primary carbide phase, and the influence on the precipitation temperature is small. The N content shows a great effect on the precipitation temperature whereas, a very limited effect on the mass fraction of the precipitated primary carbide phase. The contents of Ti and Nb have slight effect on the precipitation behaviors of the primary carbide phase in FGH96 superalloy. Therefore, the contents of C and N control the precipitation behaviors of the primary carbide phase in FGH96 superalloy. By the result of thermodynamic calculation, SEM and EDS, it can be proposed that the primary TiN containing small amount of C first precipitates from the liquid FGH96 superalloy containing N, and then the MC-type carbides precipitate on the surface of TiN in mush zone, and form a type carbonitride with TiN as core.
Key words: FGH96 superalloy; primary carbides; carbonitride; thermodynamic calculation
