Galvanic Corrosion in Molten Salts: A Discussion of the Corrosion Mechanism of Two-Phase Ni–20Cr–20/30Cu Alloys in Eutectic (Li,K)2CO3 at 650°C
Galvanic Corrosion in Molten Salts: A Discussion of the Corrosion Mechanism of Two-Phase Ni–20Cr–20/30Cu Alloys in Eutectic (Li,K)2CO3 at 650°C
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DOI：
10.1007/s11085-005-6559-3
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发表时间：
2005-10
影响因子：
2.2
通讯作者：
C. Zeng;J. Li;T. Zhou
中科院分区：
文献类型：
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作者：
C. Zeng;J. Li;T. Zhou
研究了α Ni-20 Cr和三种含10、20和30 wt.%的三元Ni-20 Cr-Cu合金的腐蚀行为Ni-20 Cr-20 Cu和Ni-20 Cr-30 Cu均为固溶体合金，而Ni-20 Cr-20 Cu和Ni-20 Cr-30 Cu均为贫Cu基体和少量富Cu相组成的两相合金。结果表明，Ni-20 Cr-Ni-20 Cr-10 Cu合金的腐蚀速率相近，均形成外层为NiO，内层为富Cr氧化物的氧化膜。两相Ni-20 Cr-20/30 Cu合金腐蚀迅速，产生富Ni-Cr氧化物和Ni-Cu金属相的混合物，这可能是贫Cu基体与合金阴极富Cu相耦合加速腐蚀的结果。与Ni-20 Cr-30 Cu相比，Ni-20 Cr-20 Cu合金由于阴极富Cu相的面积分数较小，腐蚀更严重。并对电偶腐蚀机理进行了探讨。
The corrosion of aNi–20Crand three ternaryNi–20Cr–Cualloys containing 10, 20 and 30 wt.%Cu, respectively, in a eutectic(Li, K)2CO3melt was studied at 650°C under air.Ni–20CrandNi–20Cr–10Cuare solid-solution alloys, while bothNi–20Cr–20CuandNi–20Cr–30Cuare two-phase alloys composed of aCu-depleted matrix together with a small amount of aCu-rich phase. The results indicate thatNi–20CrandNi–20Cr–10Cuhave similar corrosion rates, forming a scale of externalNiOand innerCr-rich oxides. The two-phaseNi–20Cr–20/30 Cualloys corrode rapidly, producing a mixture ofNi–Cr–rich oxidesand aNi–Cu metallic phase, which may be ascribed to the accelerated corrosion of theCu-depleted matrix coupled with the cathodicCu-rich phase of the alloys. As compared toNi–20Cr–30Cu,Ni–20Cr–20Cusuffers from more-severe corrosion, due to a smaller area fraction of the cathodicCu-rich phase in the alloy. The galvanic corrosion mechanism is also discussed.