Water Vapor Effects on the Oxidation Behavior of Fe–Cr and Ni–Cr Alloys in Atmospheres Relevant to Oxy-fuel Combustion
Water Vapor Effects on the Oxidation Behavior of Fe–Cr and Ni–Cr Alloys in Atmospheres Relevant to Oxy-fuel Combustion
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DOI：
10.1007/s11085-012-9302-x
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发表时间：
2012-05
影响因子：
2.2
通讯作者：
N. Mu;Keeyoung Jung;N. M. Yanar;G. H. Meier;F. Pettit;G. Holcomb
中科院分区：
文献类型：
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作者：
N. Mu;Keeyoung Jung;N. M. Yanar;G. H. Meier;F. Pettit;G. Holcomb
在650 °C的富氧燃烧相关气氛中研究了一些Fe-Cr和Ni-Cr基合金的氧化行为。铁素体模型合金在低p（O2）CO2+ 30%H2O和Ar + 30%H2O气体中的氧化作用大大增强。快速生长的氧化铁似乎是多孔的和透气的。从非保护性氧化到保护性氧化的转变发生在具有较高Cr含量的合金上，在H2O中的Cr含量在13.5和22重量%之间。通常在实际的富氧燃烧环境中发现的过量氧通过加速早期形成的Cr2 O3的蒸发以及由H2O诱导的加速氧化铬生长来破坏Fe-Cr合金的选择性氧化。Cr的快速消耗导致铁氧化物的成核和快速生长。相反，Ni-Cr合金受H2O和过量O2的存在影响较小。Fe-Cr和Ni-Cr合金之间的差异尚不清楚，但据推测，对于后一组合金，水蒸气对氧化铬生长的加速作用较小。
The oxidation behavior of a number of Fe–Cr- and Ni–Cr-based alloys was studied in atmospheres relevant to oxyfuel combustion at 650 °C. Oxidation was greatly enhanced in ferritic model alloys exposed in low p(O2) CO2+ 30%H2O and Ar + 30%H2O gases. Rapidly growing iron oxides appear to be porous and gas permeable. Transition from non-protective to protective oxidation occurs on alloys with higher Cr contents between 13.5 and 22 wt% in H2O. Excess oxygen, usually found in the actual oxyfuel combustion environments, disrupts the selective oxidation of Fe–Cr alloys by accelerating vaporization of early-formed Cr2O3in combination with accelerated chromia growth induced by the H2O. Rapid Cr consumption leads to the nucleation and rapid growth of iron oxides. On the contrary, Ni–Cr alloys are less affected by the presence of H2O and excess O2. The difference between Fe–Cr and Ni–Cr alloys is not clear but is postulated to involve less acceleration of chromia growth by water vapor for the latter group of alloys.