A Study of Double-coating of Hot-Dip Aluminizing

摘要

Double-coating of hot-dip aluminizing is a process of protecting steel from being oxidized. The process is featured that the component is firstly hot-dip galvanized and finally hot-dipped with aluminum. The comparison of interface morphology was conducted for single hot-dip aluminizing and double-coating of hot-dip aluminizing on Q235 steel sheets. The metallographies of the cross-sections were observed and analyzed with SEM, XRD and EDS, respectively for the specimens prepared by the two processes. The experimental results indicate that there is no Zn-Fe alloy layer formed in the double-coating, and both single and double coating have similar phase compositions. However, the interface between the alloy layer and the steel matrix is smoother for the double-coating than that for single-coating.