热浸镀铝钢扩散层的AlFe_3C_(0.5)相

AlFe_3C_(0.5) phase in diffusion layers of hot dip aluminized steel

采用740℃热浸镀铝方法,在20碳钢表面制备热浸镀铝层。镀铝层经850℃扩散处理4 h后,采用SEM和XRD确定扩散层的相组成,采用TEM研究组成相的晶体学取向关系。分析AlFe3C0.5相的形成原因。结果表明:扩散层与基体之间存在Fe3Al、FeAl和点阵常数为0.377 nm的针叶状AlFe3C0.5相;针状AlFe3C0.5与Fe3Al相之间存在的晶体学取向关系是(220)Fe3Al//(■11)AlFe 3C0.5、[1■0]Fe3Al//[■2■]AlFe 3 C0.5。

The aluminized coating on 20 carbons steel was prepared by hot dip aluminizing method at 740 ℃. After the coating diffusion treatment at 850 ℃ for 4 h, the microstructure of the interface between the diffusion layers and steel substrate was determined by scanning electronic microscopy and X-ray diffractometry, and the lattice orientation relation between constituent phases was analyzed by transmission electron microscopy. The formation mechanisms of Fe3AlC0.5 phase were also discussed. The results indicate that Fe3Al, FeAl and needle-like AlFe3C0.5 phase with lattice constant of 0.377 nm exist between the diffusion layers and steel substrate. In addition, the lattice orientation relation between AlFe3C0.5 and Fe3Al is （220）Fe3Al //（1^-11）AlFe3C0.5 , [1 1^-0]Fe3Al //[ 1^-23^-]AtFe3C0.5