Abstract Reactive air aluminization is attractive as a low-cost, simple method for preparing Al2O3 protective layer for ferritic stainless steel (FSS) components in solid oxide cell stacks. The FSS Crofer 22H is aluminized at various temperatures to obtain different levels of elements interdiffusion. The leading role of Al diffusion behavior in the process of forming the Al2O3 protective layer is investigated in detail. The roughening mechanism of aluminized surface is discussed. The formation process of Al2O3 protective layer can be divided into three stages: liquid-solid interdiffusion ( 900 °C). The intense interdiffusion between the Al liquid and the steel matrix leads to the formation of Al-containing intermetallic compounds (IMCs) layer in a short time. Increasing temperature promotes the diffusion of Al into the steel matrix, causing the phase transition of IMCs. The surface enrichment of Al suppresses the formation of Fe/Cr-oxides, ensuring the formation of a continuous, dense and crack free Al2O3 layer. The rough surface formed in the first stage basically determines the overall roughness of the sample after aluminization.

中文翻译：

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Al扩散行为在反应空气渗铝过程中形成超可靠Al2O3保护层过程中的作用

摘要 反应空气渗铝是一种低成本、简单的方法，可以为固体氧化物电池堆中的铁素体不锈钢 (FSS) 组件制备 Al2O3 保护层。FSS Crofer 22H 在不同温度下镀铝以获得不同水平的元素相互扩散。详细研究了Al扩散行为在Al2O3保护层形成过程中的主导作用。讨论了镀铝表面的粗糙化机理。Al2O3保护层的形成过程可分为三个阶段：液固相互扩散（900℃）。铝液与钢基体之间的强烈相互扩散导致在短时间内形成含铝金属间化合物（IMCs）层。升高温度促进铝扩散到钢基体中，导致 IMC 的相变。Al 的表面富集抑制了 Fe/Cr 氧化物的形成，确保形成连续、致密和无裂纹的 Al2O3 层。第一阶段形成的粗糙表面基本上决定了铝化后试样的整体粗糙度。