Effect of Hot Dip Plating Process Parameters on Microstructure and Properties of Zinc–10%Aluminum–Mischmetal Alloy Coated for Bridge Cable Steel Wire

Abstract

In this work, the effect of the hot dip plating process on the microstructure and properties of zinc–10%aluminum–mischmetal (Zn-10Al-MM) alloy coated for bridge cable wire was studied by changing the hot dip plating temperature, time, and cooling mode. An optical microscope was used to observe the microstructure of the coating and steel wire at low power; a GeminiSEM300 field emission scanning electron microscope was used to observe the microstructure of the coating and steel wire at high power. The hot dip planting temperature is 450 °C, the hot dip plating time is 30 s and 45 s, whether water cooling or air cooling, the hot dip coating structure is relatively uniform, and the grain size is small, the hot dip coating thickness is thick. The coating with 450 °C, 45 s, and the water-cooling process has the highest tensile strength. The corrosion resistance of the hot dip coatings under different processes is higher in the salt spray test. Based on the results of the electrochemical test and salt spray test, the best corrosion resistance of the coatings under 450 °C, 45 s, and the water-cooling process is obtained.