09CuPTiRE钢耐候性能及腐蚀过程研究

通过浸渍干湿循环加速腐蚀试验 ,采用失重法测量年蚀率 ,SEM观察腐蚀产物的表面形貌和断面形貌 ,XRD测定腐蚀产物的物相组成 ,电化学阻抗谱仪测定锈层的交流阻抗谱 ,研究了0 9CuPTiRE耐候钢与Q2 3 5、鞍钢耐候钢和日本耐候钢三种参比钢的耐候性能及腐蚀过程 .结果表明 :0 9CuPTiRE钢的耐候性能显著优于Q2 3 5钢 ;Q2 3 5钢锈层为一层网状、疏松且有大量纵向交错裂纹和孔洞的锈层 ,而 0 9CuPTiRE及另两种耐候钢的锈层分内外两层 ,外层与Q2 3 5钢锈层相似 ,内层均匀、连续、致密 ;Q2 3 5钢的腐蚀过程受活化控制 ,即受控于金属离子进入溶液的速度 ,而0 9CuPTiRE钢的腐蚀过程既受活化控制 ,由于保护锈层的存在还受氧的扩散控制 .

Study on the weather resistance and corrosion process of 09CuPTiRE steel

The weather resistance and corrosion process of 09CuPTiRE and Q235 steels as well as Anshan and Japanese weather resistant steels were investigated through immersion wet dry test. Weight loss method, SEM, XRD and EIS were respectively used to measure the annual corrosion rate, to observe the surface and sectional morphologies of corrosion products, to determine the substantial phase composition of corrosion products and to measure the corrosion process. The results showed that the weather resistance of 09CuPTiRE steel is remarkably better than that of Q235 steel. The rust layer of Q235 steel is a netlike and loose layer with a lot of cracks and voids, while the rust layer of 09CuPTiRE and other two weather resistant steels consists of an inner and an outer layers, in which the outer layer is similar to the rust layer of Q235 steel, but the inner layer is a homogeneous, continuous and dense one. The corrosion process of Q235 steel was dominated by the activation of steel matrix, by the diffusion rate of metallic ions into solution; while the corrosion process of 09CuPTiRE steel was dominated not only by activation of steel matrix, but also by the diffusion of oxygen due to the existence of rust layer.