中文摘要：

将Q235钢分别在Zn-6％（质量分数，下同）Al和Zn-6％Al-3％Mg合金锌浴中浸镀不同的时间，使用扫描电子显微镜（SEM）、能谱分析仪（EDS）以及X射线衍射仪（XRD）对样品合金镀层显微进行观察，分析镀层层合金层的相组成及生长过程，研究Mg对合金层生长的作用。通过研究发现，在Zn-6％A1和Zn-6％A1-3％Mg合金镀层中合金界面层组成主要是Fe-Al-Zn化合物，Fe-Al-zn合金界面层阻碍了脆性Fe-zn层的形成。Mg加入Zn-6％A1锌池中后促进了界面反应，缩短了合金层出现所需时间，并使合金层的生长更加致密均匀，稳定合金层使其不被液相侵蚀破坏而溶解。Mg的加入阻碍了扩散通道随着时间延长逐渐向两扩散组元成分点连线移动的趋势，减少了锌液进入合金层，稳定了合金层。Zn-6％Al—3％Mg镀层合金层随着时间延长而增厚，合金层的生长呈抛物线规律，主要受扩散反应控制。

英文摘要：

Zn-6%Al alloy and Zn-6%Al-3%Mg alloy coating was galvanized by hot-dip method in different immersion time to get intermetallics layer with different thickness. Samples were characterized by Scanning Electron Microscopy （SEM） and Energy Dispersive Spectroscopy （EDS） to investigate the interfacial reaction and phase composition of intermetallics layer. It is found that the hot-dip Zn- 6 % Al-3 % Mg alloy coating intermetallics layer consisted of the Fe-Al-Zn intermetallics compound, the Fe-Al-Zn intermetallics layer inhibited formation of the brittleness Fe-Zn compound layer. The addition of Mg into the Zn-6 % Al bath promotes the interface reaction and growth of the intermetallics lay- er and makes it dense. With the Mg addition, the trend of the diffusion path moving gradually to the line connecting with two diffusion component points was inhibited, and intermetallics layer would be dense. Meanwhile, the intermetallics layer becomes too stable to be eroded by the liquid zinc. The thickness of the coating increases with prolonging of dipping time. The growth of the coating in Zn- 6 %Al-3%Mg bath is controlled by diffusion.