合金元素对耐候钢腐蚀行为的协同作用机制与保护性锈层形成规律研究

Steel is an important structural material for the urban construction, and the corrosion of the steel components is a main reason for their withdrawal from work in the atmosphere, so the atmospheric corrosion of the steel can not be ignored. Weathering steel can be exposed in the atmospheric environment, and the corrosion resistance is closely related to the rust layer structure formed on the steel surface. It can be seen that the weathering steel application conforms to the new requirements of the resource saving and environment friendly society for the engineering construction. In the coastal industrial cities, the atmospheric environment presents the characteristics of coastal industrial atmosphere. As the environment is very bad, it is very difficult for the traditional weathering steel to form protective rust layer, and the steel does not play its due atmospheric corrosion resistance, so the steel is not widely used in the environment . Therefore, it is necessary to study the corrosion behaviors of the new weathering steel and the formation of protective rust layer in the environment. In this proposal, the effects of alloy elements and environmental factors on the weathering steel will be studied, and the research will reveal the mechanism of synergies during Si, Cu, Ca and Sn on the corrosion resistance of the weathering steel, and clarify the synergy mechanism of pollutants (Cl-, SO2 and NO2) on the steel corrosion and the corrosion features of the weathering steel in the aerosol environment. Moreover, the corrosion kinetics of the weathering steel, the dissolution/precipitation of corrosion products in the corrosion process and rust layer stabilization method will be studied, and the research will reveal the relationship between the dissolution/precipitation of corrosion products and the rust layer structure, and clarify the formation rule and control method of the protective rust layer in the coastal industrial atmosphere. All these investigations will provide the theoretical basis for the development of the new weathering steel and its safely long-term application in the coastal industrial atmosphere.

钢铁是城市建设的重要结构材料，而钢构件在大气中的腐蚀不容忽视。耐候钢可在大气环境中裸露使用，其符合资源节约与环境友好型社会发展对工程建设提出的新要求。在沿海工业城市中，大气环境呈现海洋工业大气特征。由于该环境较为恶劣，传统耐候钢难以形成良好保护性锈层，没有发挥其应有的耐大气腐蚀性能，限制了它的应用。故有必要针对海洋工业大气的环境特征，研究新型耐候钢的腐蚀行为以及保护性锈层形成规律。具体内容：研究Si-Cu-Ca-Sn元素间协同效应对耐候钢腐蚀性能的作用效果，分析大气环境中污染物（Cl-、SO2和NO2）对钢腐蚀的协同作用机制和气溶胶环境中耐候钢的腐蚀特性；研究耐候钢的腐蚀动力学过程、腐蚀产物在腐蚀进程中的溶解/析出机制和锈层稳定化的方法，探索腐蚀产物溶解/析出机制与锈层结构间的关系，揭示保护性锈层的形成规律和控制方法。研究结果可为研制新型耐候钢及其在海洋工业大气中安全长效使用提供理论基础。

我国沿海城市经济发达，该地区基础设施建设迅速发展，钢铁作为重要的结构材料，其在该区域环境中的腐蚀不容忽视。耐候钢可以通过钢中的少量合金元素使其在大气腐蚀过程中改变锈层的物理化学性质来抑制钢腐蚀的进程，可在大气中裸露使用，显著降低了钢构件的维护成本，具有很大的潜在经济效益。在沿海工业城市中，大气环境呈现海洋工业大气特征。由于该环境较为恶劣，传统耐候钢难以形成良好保护性锈层，没有发挥其应有的耐大气腐蚀性能，限制了它的应用。故有必要针对海洋工业大气的环境特征，研究新型耐候钢的腐蚀行为以及保护性锈层形成规律。主要研究内容和结果：研究了耐候钢表面锈层结构演变过程，分析干湿交替过程中腐蚀产物溶解/析出的规律及影响因素，构建了锈层结构演变的模型，揭示耐候钢表面保护性锈层的形成机理；研究了海洋工业大气环境中污染物对耐候钢腐蚀行为的影响，阐明了大气环境中污染物（Cl-、SO2）及其之间的协同效应对耐候钢腐蚀行为的作用机制；研究了合金元素对耐候钢腐蚀性能的影响，揭示了海洋工业大气环境中部分典型元素对耐候钢腐蚀行为的作用效果和机制；研究了海洋工业大气环境中耐候钢腐蚀动力学过程，阐明了锈层结构与钢腐蚀动力学行为之间的关系。研究结果可望为研制新型经济耐候钢及其在海洋工业大气环境中安全长效使用提供理论基础。