Corrosion Resistance of Hot Rolled Plates with Al-Zn Coating

Surface morphology of hot rolled plates with Al-Zn coating was observed by scanning electron microscopy (SEM). Neutral salt spray tests were applied to study the corrosion resistance of the hot rolled plates with Al-Zn coating. The results show that the corrosion resistance of the hot rolled plates was improved significantly as the galvanizing Al-Zn technology might fill up the pits on the surface of hot rolled plates. The corrosion rate of the hot rolled plates with Al-Zn coating first increased and then decreased with corrosion time. The white rust on the surface of Al-Zn coating was formed after 15 days, and the red rust occurred after 54 days. In addition, the corrosion kinetics model based on abundant experimental data was established, which had good fitting degree with experimental data and could provide theoretical basis for quantitative analysis of corrosion kinetics for hot rolled plates with Al-Zn coating.