About this Abstract |
Meeting |
MS&T21: Materials Science & Technology
|
Symposium
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Advanced Materials for Harsh Environments
|
Presentation Title |
Enhancing the Hardness and Corrosion Resistance of Ni-based Alloys with Thermomechanical Processing |
Author(s) |
Haruka Shima, Manami Mori, Kenta Yamanaka, Kazuo Yoshida, Akihiko Chiba |
On-Site Speaker (Planned) |
Haruka Shima |
Abstract Scope |
In this study, we examined the effect of heat treatment on the microstructure, mechanical properties, and corrosion behavior of cold-swaged Ni-30Co-16Cr-15Mo-6Fe-2Cu (mass%) alloy. An alloy rod was processed by cold swaging, with reduction in area of 50-90 %, and then annealed at 473-1273 K for various periods. The hardness of the alloy increased by cold swaging significantly. Notably, aging at 473-873 K further enhanced the Vickers hardness of the cold-swaged specimens through the nanostructural elemental evolution in the heavily deformed FCC matrix. The Cu precipitation was also observed. Although the precipitation of the Mo-rich μ-phase occurred at higher annealing temperature, the alloy was softened due to the recrystallization. Potentiodynamic polarization testing in a sulfuric acid solution revealed that such nanoscale structural evolution does not degrade the corrosion resistance of the alloy. Consequently, an excellent combination of high hardness and corrosion resistance, which exceeds that of existing corrosion-resistant superalloys, was achieved. |