Incoloy800H合金在高温纯水蒸气中的氧化行为

摘要

The oxidation behaviour of Incoloy800H alloy in 750 ℃ and 850 ℃ pure steam was investigated by discontinuous weighing method,X-ray diffraction,and scanning electron microscopy.The results show that the oxidation kinetics of the tested alloy followed a parabolic law;the oxidation accelerated rapidly with rising temperature.After oxidation in 750 ℃ steam,an oxide layer mainly composed of (Cr,Mn)2O3 was formed on the surface of the tested alloy,discontinuous bulgy Fe3 O4 was distributed on the oxide layer and Cr in the matrix under the oxide layer was oxidized internally to Cr2O3 .After oxidation in 850 ℃ steam,a duplex oxide layer,composed of a thin outer layer of (Fe,Mn)3 O4 and a thick inner layer of (Cr,Mn)2O3 ,was formed on the surface of the tested alloy;beneath the oxide layer,Al was oxidized inernally to Al2O3 along grain boundaries in the matrix.%采用不连续称重法、X射线衍射及扫描电子显微镜等研究了Incoloy800H合金在750℃和850℃纯水蒸气中的氧化行为.结果表明:试验合金的氧化动力学近似遵循抛物线规律,温度升高后其氧化急剧加速;在750℃蒸汽中氧化后,试验合金表面形成以(Cr,Mn)2O3为主的氧化膜,其上分布着不连续呈突起状的Fe3O4,在氧化膜下方基体中的铬被内氧化为Cr2O3;在850℃蒸汽中氧化后,试验合金表面形成双层氧化膜,外层为薄的(Fe,Mn)3O4,内层为厚的(Cr,Mn)2O3,氧化膜下方基体中的铝沿晶界发生内氧化生成Al2O3.