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为了解新型难变形镍基高温合金ЭК151的铸态组织特点,并为制定均匀化工艺打下理论基础,本文利用光学显微镜、扫描电镜和能谱分析研究了ЭК151合金铸锭的偏析特征;通过1100~1250℃的均匀化实验和不同温度均匀化过程的元素扩散动力学计算,研究了合金的均匀化工艺。结果表明,ЭК151合金凝固过程中,Nb、Mo、和Ti等元素在枝晶间偏析,并形成大量的γ′+γ共晶相;为保证γ′相、共晶相回溶彻底,元素扩散充分,需要在1200℃以上进行均匀化处理;针对Nb元素的扩散动力学计算结果给出了不同温度均匀化处理所需要的时间。
In order to understand the as-cast microstructure of the new type of hard-deformation nickel-base superalloy ЭК151 and lay a theoretical foundation for the development of homogenization process, the segregation characteristics of ЭК151 alloy ingot were studied by optical microscope, scanning electron microscopy and energy spectrum analysis. 1250 ℃ homogenization experiment and elemental diffusion kinetics calculation under different temperature homogenization process, the alloy homogenization process was studied. The results show that Nb, Mo, Ti and other elements segregate between dendrites and form a large amount of γ ’+ γ eutectic phase during the solidification of ЭК151 alloy. In order to ensure the γ’ phase, the eutectic phase is completely dissolved and the elements diffuse Sufficient, it needs to be homogenized above 1200 ℃; the diffusion kinetics calculation result of Nb element gives the time needed for different temperature homogenization treatment.