Corrosion Resistance of Zn-22Al-Mg-RE Coating Prepared by Twin Wire Arc Spraying

Abstract:

Zn-22Al-Mg-RE alloy coating was prepared on Q345 steel substrate by arc spraying with alloy wires which were researched and designed independently. The microstructure and corrosion resistance of the Zn-22Al-Mg-RE alloy coating were investigated and compared with that of Zn coating by SEM, Copper-accelerated acetic acid salt spray, XRD and Polarization curves. Results show that the bonding strength of Zn-22Al-Mg-RE alloy coating is increased by 40% compared with that of pure zinc coating?, and the first rust appearing time is prolonged by 1 time in Copper-accelerated acetic acid salt spray test. Electrochemical experiment results show that the corrosion resistance of Zn-22Al-Mg-RE alloy coating is superior to that of pure Zn coating. It is indicated that the appearance of much Zn6Al2(OH)16CO3·4H2O which is stable and dense, is one of the main reasons for the enhanced corrosion resistance of the Zn-22Al-Mg-RE alloy coating