铁素体不锈钢室温熔盐镀铝层的热处理

Heat treatment of aluminum coating electrodeposited on ferritic stainless steel at room temperature molten salts

以1Cr17铁素体不锈钢为基体,在摩尔比2∶1的酸性AlCl3-EMIC(1-甲基-3-乙基咪唑氯化物)室温熔盐中电沉积均匀致密的铝镀层,然后分别在300℃、650℃6、70℃下进行不同时间的热处理,用刻划撕扯法判断镀层的结合力,用SEM、EDS及XRD对热处理后的试样界面进行微观分析。结果表明,试样经热处理后,结合力有了很大提高,镀层与基体之间发生互扩散形成合金层,合金层由含Cr的Fe2Al5、FeAl、Fe3Al等相组成,且随着温度提高及热处理时间的增长,镀层由Fe2Al5相进一步转变成铁含量高、韧性高的FeAl、Fe3Al相。

The dense, uniform aluminum coating electrodeposited on 1Crl7 ferritic stainless steel in acid AlCl3-EMIC （2：1） room temperature molten salts was heated at 300℃, 650℃, 670℃ for different time. The adhesion strength of the coating was qualitatively estimated by scoretearing test. The interface between coating and substrate was analyzed by EDS, SEM and XRD. The results show that the adhesion strength of the coating to substrate is greatly improved after heat treatment, and metallurgical interface layer composed of Fe2 Al5 , FeAl, Fe3 Al phases containing Cr is forms by interdiffusion of elements between the aluminum coating and substrate. With the increase of temperature and time of heat treatment, Fe2 Al5 phase in the interface layer transforms into FeAl, Fe3 Al phases with high iron content and high toughness.