中文摘要：

对经不同扩散工艺处理的热浸镀铝层高温抗氧化性进行了研究，通过SEM、TEM、XRD分析了经扩散处理后，热浸镀铝层高温氧化过程中组织结构的变化情况，分析了热浸镀铝层高温抗氧化性能和微观结构的关系，确定了提高热浸镀铝层高温抗氧化性的适宜扩散温度。结果表明，经750℃扩散处理，热浸镀铝层结构由较厚的外表层（Fe2Al5＋FeAl2）及内层（FeAl＋条状FeAl2）组成，条状FeAl2的形成为氧提供了扩散通道，其抗氧化性较差：经950℃扩散处理，镀层外表层变薄，外表层转为单一FeAl2、内层为FeAl，并出现早期内氧化裂纹，其抗氧化性较差；当扩散处理温度为850℃时，镀层外表层变薄，结构转为FeAl2＋少量Fe2Al5，而内层增厚，其结构为FeAl＋球状FeAl2，而内层FeAl2球化，增强了氧由内层向基体扩散的阻碍作用，使氧只能逐层形成Al2O3＋Fe2O3的氧化膜，提高了镀层的高温抗氧化性。

英文摘要：

The effect of diffuse treatment on hot-dip aluminizing steel microstructure and oxidation resistance behavior at high-temperature in air was studied by means of TEM, SEM and XRD. The results show that the diffusion temperature has significant effect on the structure of coatings and its oxidation resistance. After diffusion at 750℃, the coating consisted of thicker outer layer （Fe2Al5＋FeAl2） and thinner internal layer（FeAl2＋stripe FeAl2）, the oxidation resistance of the coating was poor. After diffusion at 950℃, the outer layer was single FeAl2 phase, the internal layer was FeAI phase, the oxidation resistance of the coating declined due to the occurrence of early stage internal oxidation cracks in the coating. After diffusion at 850℃, the outer layer became thinner and consisted of FeAl2＋Fe2Al5 （small amount）, the internal layer became thicker and consisted of FeAl ＋ spherical FeAl2, the FeAl2 phase in the internal layer were spherioidized, resulting in hindering the diffusion of oxygen into the matrix, thus making oxygen forming Al2O3＋Fe2O3 oxidation film only, finally the coating oxidation resistance of were improved.