铁路钢桥电弧喷Al长效防腐蚀技术研究

Research on Long Life Anti Corrosion of Railway Bridge by Arc Sprayed Coating

针对铁路钢桥的腐蚀状况，对电弧喷涂长效防腐技术进行了分析研究。通过电弧喷涂Ａｌ、Ｚｎ涂层的显微组织分析，阳极极化曲线的测定、中性盐雾加速试验和电弧喷涂Ａｌ涂层的防腐寿命估算表明：Ｚｎ涂层较Ａｌ涂层致密，两种涂层的极化曲线都比较平缓，Ａｌ涂层的极化曲线出现了一个准钝化区；两种涂层的自腐蚀电位都要比同材料的铸造组织更低一些；电弧喷涂Ａｌ涂层加封孔剂的复合涂层的耐腐蚀寿命可达３０年以上。

The study on long life anti corrosion by arc sprayed coating was carried out according to current corrosion situation of railway bridge.The microstructure of arc sprayed Al,Zn coatings are studied by means of SEM,XRD,etc.The potentiostatic anodic polarization curves,salt mist and anti corrosion in organic acid environment of arc sprayed coatings have been tested.At the same time,the corrosion lifetime of arc sprayed Al coatings was evaluated.The results show that the Al,Zn coatings is mechanically mixed by Al,Zn phases,the microstructure of this coating is fine and regular,the potentiostatic anodic polarization curves of Al,Zn coatings go on gently and little inactivation appears on the curve of Al coating,the spontaneous electrocal potential of Al,Zn coating are -0.915V and -1.065V respectively in 3.0% NaCl solution, and the spontaneous electrocal potential of Al,Zn coating are more negative than that of such casting materials,and the corrosion lifetime of Al coating on the railway bridge can be maintained over 30 years.