Corrosion Resistance of Hot Dipping Al-Zn-Si and Zn-Al-Mg-Si Alloy Coating

摘要

A comparative research on the characteristics and corrosion resistance of two kinds of hot dipping alloy coating section for 55%Al-43.5%Zn-1.5%Si and Zn-11%Al-3%Mg-0.2%Si. The distribution and organization of the cross-sectional elements were analyzed by glow discharge apparatus and metallurgical microscope. And electrochemical workstation was applied to test Tafel polarization curves and electrochemical impedance spectroscopy. The results showed that 55% zinc Al-43.5%-Si alloy coating surface was mainly Al and Zn, near the inner side main ingredients for Fe, Al, and the corrosion potential of 1050.7 mV; Zn-11%Al-3%Mg-0.2%Si alloy coating surface composition was mainly Zn, Al, Mg, and close to the inside the main components is Fe, Zn, the corrosion potential of -710.7 mV. The corrosion resistance of 55%Al-43.5%Zn-1.5%Si alloy coating was significantly better than the Zn-11%Al-3%Mg-0.2%Si coating.