Reaction morphologies developed by nickel aluminides in type II hot corrosion conditions: The effect of chromium
Reaction morphologies developed by nickel aluminides in type II hot corrosion conditions: The effect of chromium
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DOI：
10.1016/j.corsci.2015.08.029
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发表时间：
2015-12
影响因子：
8.3
通讯作者：
Thomas Gheno;M. Z. Azar;A. Heuer;B. Gleeson
中科院分区：
文献类型：
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作者：
Thomas Gheno;M. Z. Azar;A. Heuer;B. Gleeson
Ni-36Al（at.用扫描电镜和透射电镜研究了Ni-36 Al-5Cr合金在700 °C、O2- 0.1%SO2中添加Na 2SO 4后的组织变化。NiAl上的保护膜的局部失效通过内氧化导致结核的发展。相反，NiAlCr经历了一个统一的攻击，涉及内部硫化，多孔规模的增长，和NiO和Al 2 O3溶解到硫酸盐。通过比较暴露于空气和O2- 0.1%SO2中的Na 2SO 4、Na 2SO 4-MgSO 4和Na 2SO 4-Cr2 O3沉积物，研究了气体和硫酸盐成分的作用。Cr在早期暴露过程中防止钝化的效果与NiO和Cr2 O3的耦合溶解有关。
The short-term reaction of Ni–36Al (at. %) and Ni–36Al–5Cr alloys with Na2SO4in O2-0.1% SO2at 700 °C was studied by SEM and TEM. Local failure of the protective scale on NiAl led to nodule development via internal oxidation. Conversely, NiAlCr underwent a uniform attack involving internal sulfidation, porous scale growth, and NiO and Al2O3dissolution into the sulfate. The roles of gas and sulfate compositions were studied by comparing exposures to Na2SO4, Na2SO4–MgSO4and Na2SO4–Cr2O3deposits in air and O2-0.1% SO2. The effect of Cr in preventing passivation during early-stage exposure was associated with a coupled dissolution of NiO and Cr2O3.