摘要
为了改善钢铁材料的耐高温腐蚀性能,用光束合金化方法在45钢表面合成了Fe-Al金属间化合物涂层。采用扫描电子显微镜、能量弥散X射线分析和X射线衍射研究了光束合金化工艺参数(粉末预置量m和热输入量q)对合金化层的化学成分、显微组织及其物相组成的影响。实验结果表明:减小比能量(E=q/m)将导致合金化层的熔宽和熔深减小,从而使合金化层含Fe量减少,含Al量增加;该实验条件下,获得了Fe/Al原子数比为2.4～19.2的合金化层。由比能量决定的Fe/Al原子数比是合金化层显微组织及其物相组成的重要影响因素,合金化层的显微组织有3种类型:α-Fe固溶体、α-Fe固溶体+Fe3Al金属间化合物及FeAl+AlFe3C0.5金属间化合物。降低热输入或增加粉末预置量均可引起合金化层中Fe/Al原子数比的降低,有助于Fe-Al系(Fe3Al或FeAl)金属间化合物的合成。
The high temperature corrosion resistance of steel was improved with a Fe-Al intermetallic coating applied to Steel-45 by light beam alloying. The effect of alloying processing parameters (the preplaced powder mass, m , and the heat input, q ) on the chemical composition, microstructure and phases of the alloying coatings was investigated by scanning electron microscopy, energy dispersive X-ray analysis, and X-ray diffraction. The results show that reducing the specific heat input E (E=q/m) reduces the width and penetration of the alloying molten pool, which reduces the Fe content and increases the Al content of the coatings. The experiments resulted in coatings with 2.4~19.2 Fe/Al atomic ratios. The Fe/Al atomic ratio determined by the specific heat input is the most important factor affecting the microstructure and phases of the coatings. There are three kinds of coating microstructures, α-Fe solid solution, α-Fe solid solution +Fe3Al intermetallic compound, and FeAl+AlFe3C0.5 intermetallic compounds. Reducing the heat input and increasing the preplaced powder mass both reduce the Fe/Al atomic ratio of the coatings, which favors the synthesis of the Fe-Al (Fe3Al and FeAl) intermetallic compounds.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2004年第5期585-588,共4页
Journal of Tsinghua University(Science and Technology)
基金
国家自然科学基金资助项目(50275082)
