Abstract A Ni2Al3 coated tube was exposed in a wood firing power plant for 7100 h. The exposure resulted in protective behaviour in most areas, while corrosion attack occurred in local areas. In areas exhibiting protective behaviour, a 30−50 nm thick γ-Al2O3 layer was found, and a 200−250 nm K–O rich amorphous layer was identified in the corroded area. A corrosion mechanism is suggested: γ-Al2O3 was broken down by reaction with KCl(g) resulting in formation of potassium aluminate. Migration of Cl through potassium aluminate resulted in formation of volatile AlCl3. KCl-AlCl3 then led to alumina fluxing and further corrosion attack.

中文翻译：

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γ-Al2O3在生物质发电厂暴露的Ni2Al3涂层上的分解机制

摘要 Ni2Al3 涂层管在燃木发电厂中暴露了 7100 小时。暴露在大多数地区产生了保护行为，而在局部地区发生了腐蚀攻击。在表现出保护行为的区域，发现了 30-50 nm 厚的 γ-Al2O3 层，并在腐蚀区域发现了 200-250 nm 的富含 K-O 的非晶层。提出了一种腐蚀机制：γ-Al2O3 与 KCl(g) 反应分解，导致形成铝酸钾。Cl 通过铝酸钾的迁移导致形成挥发性的 AlCl3。KCl-AlCl3 然后导致氧化铝熔剂和进一步腐蚀侵蚀。