Study on growth factors of intermetallic layer within hot-dipped 25% Al-Znalloy coating on steel

25%Al-Zn alloy coating performs better than hot dip galvanized coating and 55%Al-Zn-Si coating with regard to general seawater corrosion protection. T his study deals with the interfacial intermetallic layer's growth, which af fects considerably the corrosion resistance and mechanical properties of 25 %Al-Zn alloy coatings, by means of three-factor quadratic regressive orthog onal experiments, The regression equation shows that the intermetallic laye r thickness decreases rapidly with increasing content of Si added to the Zn -Al alloy bath, increases with rise in bath temperature and prolonging dip time. The most effective factor that determined the thickness of intermetal lic layer was the amount of Si added to Zn-Al alloy bath, while the effect of bath temperature and dip time on the thickness of intermetallic layer we re not very obvious.