China Nonferrous Metallurgy

Thanks to the excellent corrosion resistance, high notch self-healing and formability of Zn-Al-Mg alloy coating, the preparation of high-purity Zn-Al-Mg alloy has become a research focus of large steel enterprises at home and abroad. Two Zn-2%Al-2%Mg and Zn-5%Al-5%Mg alloys for hot galvanizing were prepared by power frequency induction furnace in Henan Yuguang Zinc Industry Co., Ltd., and by analyzing the microstructure and composition segregation of the alloys, it is found that the microstructure of the alloys is uniformly dispersed, and there is no inclusion and oxide. The solidification microstructure of Zn-2%Al-2%Mg is mainly composed of primary Zn phase, Zn/MgZn₂ binary eutectic structure and Zn/MgZn₂/Al ternary eutectic structure. There are lots of coarse Al/MgZn₂ binary eutectic and coarse Mg₂Zn₁₁ phase in the solidification microstructure of Zn-5%Al-5%Mg. The remelting experiment of Zn-2%Al-2%Mg shows that no oxide slag exists after remelting. Through the analysis of alloy ingot from transverse and longitudinal sampling, it is found that the transverse segregation of aluminum and magnesium is small, and the longitudinal segregation is about 0.1%. This paper provides a description on the detailed process and technological parameters of Zn-Al-Mg alloy preparation experiment, with an expectation to serve as a reference for researchers in this field.