On the Competitive Growth of Alpha and Transient Aluminas During the First Stages of Thermal Oxidation of FeCrAl Alloys at Intermediate Temperatures
On the Competitive Growth of Alpha and Transient Aluminas During the First Stages of Thermal Oxidation of FeCrAl Alloys at Intermediate Temperatures
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FeCrAl合金中温热氧化第一阶段α和瞬态氧化铝的竞争生长
DOI：
10.1007/s11085-008-9126-x
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
A. Galerie
中科院分区：
文献类型：
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作者：
R. Chegroune;E. Salhi;A. Crisci;Y. Wouters;A. Galerie
许多研究致力于FeCrAl合金在850-950℃的中温范围内的氧化，在那里观察到“异常”的氧化物生长[1-3]。这种现象被描述为过渡期，在该过渡期中，亚稳立方氧化铝的向外生长比稳定的菱面体α-氧化铝向内生长更快，这有效地保护了这类合金高达1200℃。因此，由于亚稳氧化铝生长而从合金中更快地消耗铝在必须使用薄金属箔的情况下尤其有害，例如在内燃机排气系统中的催化剂载体的情况[4-6]，并且必须被理解和抑制或减少。先前的研究通常得出结论，瞬时亚稳氧化铝，其特征是取决于合金的C、D和/或H变形，使用的温度和表征技术[7]，在氧化的第一分钟内迅速形成并生长，呈现典型的针状或片状。动力学遵循接近抛物线的行为，具有高速率常数(KPS)，这在文献中得到了广泛的报道；例如，参见[8]。这些氧化铝改性物在形成方面都是稳定的
Many studies have been devoted to the oxidation of FeCrAl alloys in the intermediate temperature range 850–950 C, where ‘‘abnormal’’oxide growth is observed [1–3]. This phenomenon has been described as a transition period in which the outward growth of metastable cubic aluminas is more rapid than the inward growth of the stable rhombohedral a-alumina, which effectively protects this type of alloy up to 1200 C. The consequently more rapid consumption of aluminum from the alloy due to metastable Al2O3 growth is particularly detrimental in situations where thin metallic foils have to be used, as in the case of catalyst supports in exhaust systems of combustion engines [4–6], and has to be understood and suppressed or reduced.Previous studies have generally concluded that the transient metastable aluminas, characterized to be c, d and/or h modifications depending on alloy, temperature and characterization technique used [7], quickly form in the first minutes of oxidation and grow showing typical needle or platelet shapes. Kinetics follow near parabolic behavior, with high rate constants (kps), extensively reported in the literature; see for example [8]. These alumina modifications are all stable regarding their formation