热浸镀Zn-Al-Mg合金过渡层组织的研究

Microstructure of interface layer of hot-dip galvanizing Zn-Al-Mg alloy coating

为了获取性能更佳的界面组织,探究了Mg元素对热浸镀Zn-Al合金界面组织的影响.以热浸镀广泛应用的Galfan合金为基础,在其中加入不同含量的Mg元素,将其作为镀液进行热浸镀实验,对浸镀后样品的截面与腐蚀后表面进行观察与分析.阐述了热浸镀Zn-Al-Mg合金过渡层组织及性能特点.实验表明,热浸镀Zn-AlMg合金过渡层厚度随温度升高而增大,当温度达到540℃时,过渡层厚度达到最大值.Mg元素可以细化晶粒,提高Mg含量可使过渡层与基体界面趋于平直,使过渡层变薄.Mg原子在反应过程中渗入Fe-Al化合物中,改变了其晶体结构,使组织更加致密并提高了过渡层的显微硬度.

In order to get better interface organization,this paper explores the effect of Mg on the interface microstructure of hot-dip Zn-Al alloy. This paper is based on Galfan which is widely used. The dipped section and surface corrosion samples were observed and analyzed while putting difficult contents of Mg into Galfan for hot dip experiments. The characteristics of microstructure and performance of interface layer of hot-dip galvanizing Zn-Al-Mg alloy coating is expounded. Results show that the thickness of hot dip Zn-Al-Mg alloy interface layer increases with the temperature：when the temperature is 540℃, the thickness of the interface layer reaches the maximum.Mg can refine grain, increasing the content of Mg can make the interface near matrix tend to be straight and make the interface thinner.Mg atoms penetrate into the Fe-Al compounds in the reaction process, and the crystal structure of the Fe-Al compound is changed, thus making the microstructure denser and the micro hardness is increased.