Improving oxidation resistance of Ni-16Mo-7Cr-4Fe nickel-based superalloy by yttrium microalloying

Subjects: Nuclear Science and Technology >> Particle Accelerator submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》

LI Xiao-Li HE Shang-Ming ZHOU Xing-Tai LI Zhi-Jun ZOU Yang LI Ai-Guo YU Xiao-Han

Abstract： Microstructure and oxidation behavior of modified Ni-16Mo-7Cr-4Fe alloys by yttrium microalloying were investigated by scanning electron microscopy, transmission electron microscopy, grazing incident X-ray diffraction and synchrotron radiation X-ray fluorescence. M₆C and Ni₁₇Y₂ phases were observed and the amount of Ni₁₇Y₂ increased with yttrium concentration. When the yttrium concentration increased to 0.43wt.%, some Ni₁₇Y₂ chains and multi phase regions containing Ni₁₇Y₂, M₆C and γ phase appeared, which is harmful for the oxidation resistance. The alloy containing 0.05wt.% yttrium showed the best oxidation resistance, which derives its oxidation resistance from the adequate concentration of yttrium in the solid-solution (γ phase), the formation of the protective layer of YCrO₃ and chromia oxide and the strengthening effect of yttrium on oxide boundaries.

YES

 Hits 856  Downloads 214  Comment 0