Hot Corrosion of an Electrodeposited Ni-11 wt % Cr Nanocomposite under Molten Na2SO4 – K2SO4 – NaCl
Hot Corrosion of an Electrodeposited Ni-11 wt % Cr Nanocomposite under Molten Na2SO4 – K2SO4 – NaCl
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DOI：
10.1149/1.1952667
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发表时间：
2005-09
影响因子：
3.9
通讯作者：
Cuimiao Zhang;X. Peng;Jiangyuan Zhao;Fu-Xin Wang
中科院分区：
文献类型：
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作者：
Cuimiao Zhang;X. Peng;Jiangyuan Zhao;Fu-Xin Wang
通过从硫酸镍浴中同时电沉积 Ni 和 Cr 纳米颗粒，将平均 Cr 浓度为 11（wt%）的 Ni-Cr 纳米复合材料沉积到镍板上。该纳米复合材料由纳米晶镍基体和分散的平均尺寸为 33 nm 的 Cr 纳米颗粒组成。为了进行比较，使用电弧熔炼制备了两种 Ni-Cr 合金，一种具有相似的 Cr 含量 (10 wt%)，另一种具有更高的 Cr 含量 (20 wt%)。 700℃空气中熔融Na2SO4-K2SO4-NaCl下的热腐蚀测试表明，快速形成连续的富铬垢对于热腐蚀防护至关重要。仅纳米复合材料的情况如此。电弧熔炼合金观察到内部硫化，但纳米复合材料未观察到内部硫化。结果表明，纳米复合材料具有优异的耐热腐蚀性，主要不是铬含量的影响，而是纳米复合材料独特的结构。保护机制在于纳米复合材料上快速形成连续的氧化铬鳞片，因为氧化铬很容易在铬纳米颗粒和丰富的镍晶界上成核，然后由于铬通过这些晶界的扩散增强而使核快速连接。 (c) 2005 年电化学协会。
A Ni-Cr nanocomposite with an average Cr concentration of 11 (wt %) was deposited onto nickel plate by simultaneous electrodeposition of Ni and Cr nanoparticles from a nickel sulfate bath. The nanocomposite consisted of a nanocrystalline Ni matrix and dispersed Cr nanoparticles with a mean size of 33 nm. For comparison, two Ni-Cr alloys, one with similar Cr content (10 wt %) and the other with much higher Cr content (20 wt %), were prepared using electro-arc melting. Hot corrosion testing under molten Na2SO4-K2SO4-NaCl in air at 700 degrees C showed that rapid formation of a continuous chromia-rich scale is essential for hot corrosion protection. This was the case only for the nanocomposite. Internal sulfidation was observed for arc-melted alloys, but not for the nanocomposite. The results demonstrate that it was not primarily the Cr content but the unique structure of the nanocomposite that was responsible for its superior hot corrosion resistance. The protection mechanism lies in the fast formation of a continuous chromia scale on the nanocomposite, due to the easy nucleation of chromia on both chromium nanoparticles and abundant nickel grain boundaries, and then fast linking of the nuclei as a result of enhanced diffusion of Cr through those grain boundaries. (c) 2005 The Electrochemical Society.