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Vol.46, No.10, 646 ~ 652, 2008
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| Title |
| Hot Corrosion Behavior of Plasma-Sprayed Partially Stabilized Zirconia Coatings in a Lithium Molten Salt |
| 조수행 Soo Haeng Cho , 홍순석 Sun Seok Hong , 강대승 Dae Seong Kang , 박병흥 Byung Heong Park , 허진목 Jin Mok Hur , 이한수 Han Soo Lee |
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| Abstract |
| The electrolytic reduction of spent oxide fuel involves the liberation of oxygen in a molten LiCl electrolyte, which results in a chemically aggressive environment that is too corrosive for typical structural materials. It is essential to choose the optimum material for the process equipment handling molten salt. IN713LC is one of the candidate materials proposed for application in electrolytic reduction process. In this study, yttria-stabilized zirconia (YSZ) top coat was applied to a surface of IN713LC with an aluminized metallic bond coat by an optimized plasma spray process, and were investigated the corrosion behavior at 675℃ for 216 hours in the molten salt LiCl-Li2O under an oxidizing atmosphere. The as-coated and tested specimens were examined by OM, SEM/EDS and XRD, respectively. The bare superalloy reveals obvious weight loss, and the corrosion layer formed on the surface of the bare superalloy was spalled due to the rapid scale growth and thermal stress. The top coatings showed a much better hot-corrosion resistance in the presence of LiCl-Li2O molten salt when compared to those of the uncoated superalloy and the aluminized bond coatings. These coatings have been found to be beneficial for increasing to the hot-corrosion resistance of the structural materials for handling high temperature lithium molten salts. |
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| Key Words |
| plasma spray coating, yttria-stabilized zirconia coat, hot corrosion, structural material, electrolytic reduction |
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