采用真空蒸镀方法在镀锌钢板表面沉积一定厚度的镁,然后对其进行合金化退火处理获得了新型锌镁合金镀层.通过扫描电子显微镜(SEM)观察了镀层表面及截面、切边的微观组织,利用能谱(EDS)进行了微区成分分析;应用盐雾试验,电化学方法对锌镁镀层钢板的耐蚀性进行了研究,利用X射线衍射分析了镀层及镀层盐雾试验腐蚀产物的物相组成.结果表明,蒸镀锌镁镀层主要由MgZn2及其他锌镁合金相组成,锌镁镀层比普通镀锌板具有更强的耐腐蚀性能,同时有更好的切边耐腐蚀性能.在宏观上表现为蒸镀锌镁镀层腐蚀产物相对于纯锌镀层更加致密,在电化学行为上表现为蒸镀锌镁镀层具有更小的腐蚀电流密度和更高的极化电阻.

Magnesium layers with a certain thickness on conventionally galvanized steel sheets were prepared by the vacuum evaporation coating technology.And then the coated sheets were treated by alloying and annealing processes in order to obtain novel Zn-Mg alloy coatings.The surface,cross and cutting edge section microstructure of Zn-Mg alloy coatings were analyzed by SEM and EDS.The anti-corrosion performance of Zn-Mg alloy coatings were studied by salt spray test and electrochemical experiment.Coatings themselves and the corrosion products were analyzed by X-ray diffraction.It was proved that the Zn-Mg alloy coating was mainly composed of MgZn2 and other zinc-magnesium alloy phase.The Zn-Mg alloy coating has even more excellent corrosion resistance and better corrosion resistance of cutting edges than conventionally galvanized steel sheet.Regarding to the macro performance,the corrosion products zinc magnesium coating are more compact than those of the pure zinc coating,and the electrochemical behavior of zinc magnesium coating has a smaller corrosion current density and higher polarization resistance.