空调通风管道用镀锌钢板的耐腐蚀性能研究

Study on Corrosion Resistance of Galvanized Steel Sheet for Ventilating Duct in Air Conditioning

采用SEM、电化学性能、EDS和XRD等手段,对空调通风管道用热镀锌钢板在不同pH值溶液中的腐蚀形貌和电化学性能进行了研究。结果表明,表面镀锌层与基体钢板结合良好,镀锌层厚度约在65μm左右;在pH值从12.5上升至13.5过程中,自腐蚀电流密度加大,钢板的耐腐蚀性能降低;热镀锌钢板从基材至镀锌层分别为Fe元素(α-Fe)、Fe_3Zn_(10)相(Г)、FeZn_7相(δ)、FeZn_(13)相(ζ)和Zn层(η);热镀锌钢板的腐蚀产物主要为ZnO和片状晶体Ca[Zn(OH)_3]_2·2H_2O。

The corrosion morphology and electrochemical properties of a hot-dip galvanized steel strip in different pH solution was analyzed by means of SEM, electrochemical, EDS and XRD methods. The results show that the surface coating and the base plate are in good combination, the thickness of galvanized layer is about 65μm; the corrosion potential and corrosion current density has not obvious regularity in different pH solution. When the pH value increases from 12.5 to 13.5, the corrosion current density increase, and the corrosion resistance of the pipeline is reduced. The pipeline section morphology fxom substrate to galvanized layer respectively is Fe elements （α-Fe）, Fe3Zn10 phase （Г）, FeZn7 （δ）, FeZn,3 （ζ） and Zn （η） layers. The surface corrosion products of the steel are mainly ZnO and lamellar crystal Ca[Zn （OH）3]2·2H2O.