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采用不同的镀铝温度在20碳钢上制备了不同厚度的热浸镀铝层,通过测量热浸镀铝层厚度以及高温氧化后渗铝层/基体界面空洞平均直径和形核数量随氧化时间的变化,研究了镀铝温度对渗铝层/基体界面空洞生长的影响。结果表明：随镀铝温度升高,镀铝后的表面层厚度减小,合金层厚度增加;在高温氧化期间,渗铝层/基体界面空洞的生长速度随镀铝温度的升高而减小,其变化规律与热浸镀铝后表面层厚度随镀铝温度的变化规律相一致;界面空洞平均深度随镀铝温度升高而增加,其变化规律与热浸镀铝后合金层厚度随镀铝温度的变化规律相一致;界面空洞增量随氧化时间的延长先增加而后逐步减少,且镀铝温度越高,空洞形核速度越小。分析了镀铝温度对界面空洞生长的影响机制。

Aluminized layer with different thickness on a low carbon steel was prepared by hot tip aluminizing process at different temperatures.The effects of aluminizing temperature on formation and growth of voids along interface between aluminized layer and steel substrate were investigated by cyclic oxidation test and measuring of variations of the average size and number of the voids with oxidation time.The results show that the aluminized layer consists of surface layer and alloy layer,and the thickness of surface layer decreases gradually and thickness of alloy layer increases gradually with increasing aluminizing temperature.The growth speed of the voids decreases gradually with increasing aluminizing temperature during high temperature oxidation and its variations regulation are in accord with the variations regulation of the thickness of the surface layer with aluminizing temperature.However the average depth of the voids in the aluminized layer increases gradually with increasing aluminizing temperature and its variations are in accord with the variations of the thickness of the alloy layer with aluminizing temperature.The increment of voids increases first and then decreases gradually with increasing oxidation time,and the higher aluminizing temperature,the lower the nucleation rate of the void is.The influence mechanism of aluminizing temperature on growth of the voids is also analyzed.