热浸镀锌铝镁镀层微观组织试验

 研究了热浸镀工艺对于镀层的微观结构的影响，利用扫描电镜（SEM）及能谱分析（EDX）观察了Zn-Al-Mg镀层表面以及截面的微观结构、合金层的形貌、镀层中各相的成分组成，利用辉光放电发射光谱仪(GDS)分析了镀层中各元素沿深度方向的分布，利用电子探针（EPMA）分析了镀层中各元素的分布，利用X射线光电子能谱（XPS）分析了镀层表面元素，利用X射线衍射(XRD)分析了镀层的相组成。结果表明，镀层中各元素沿镀层的深度方向的分布并不均匀，Mg在镀层表面富集，镀层组织呈现多相混合结构，以Zn晶粒、MgZn2与Zn组成的共晶为主，同时存在块状富铝相以及一层较薄的合金层。

Experiments Investigation on Microstructure of Galvanized Zn-Al-Mg Coated Steel Sheet

The facts of galvanizing parameters on microstructure of hot-dipped Zn-Al-Mg coated steel sheet were investigated. The surface and cross sectional microstructure of Zn-Al-Mg coating and the chemical composition and the morphology of alloy layer were analyzed by SEM and EDX. The element distribution in the depth direction of coating was analyzed by GDS. The element distribution in coating was analyzed by EPMA. The phase composition of coating were analyzed by XRD. The elements’ content in coating was explored by XPS. It is proved that the distributions of elements are asymmetry in the depth direction in coating, and zinc and magnesium is enriched in coating surface. Coating structure takes on multiphase commix, MgZn2 and pure zinc binary eutectic are the main phase and at the same time there are some zinc-rich nubby phase and a filmy alloy layer.