采用热浸镀方法在Q235钢板表面制备了Mg的质量分数分别为0.0%，0.1%，0.3%，0.5%的锌基合金镀层。利用扫描电子显微镜（SEM）、能谱仪（EDS）、辉光光谱仪（GDOES）等手段分析了Mg含量变化对镀层组织结构的影响。结果表明：随着镀层中Mg含量的增加，合金镀层的表面晶粒逐渐变小；Mg元素富集于晶界之中，起到细化晶粒的作用；Mg推迟了ζ相向δ相的转变，使镀层结构中的δ相层减薄。

Hot-dip galvanizing was used to prepare zinc-based alloys on the surface of Q235 steel sheet. The alloys contains various Mg contents of 0wt%, 0.1wt%, 0.3wt%, 0.5wt%, respectively. SEM, EDS and GDOES were used to analyze the effect of Mg content on the microstructure of alloys. The results show that with the increase of the content of Mg in the coating, the grain size of coating decreased. Mg segregated in grain boundaries and played a role of fining the grain size. Mg is capable of hindering the transformation of ζ phase to δ phase, resulting in thin δ phase layer.