混凝土环境中奥氏体不锈钢在应力作用下的钝化性能及孔蚀萌生特征研究

项目名称： 混凝土环境中奥氏体不锈钢在应力作用下的钝化性能及孔蚀萌生特征研究

项目编号： No.51301060

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 冯兴国

作者单位： 河海大学

项目金额： 25万元

中文摘要： 钢筋的锈蚀是导致混凝土结构耐久性不足的主要原因。不锈钢钢筋不仅可以保证混凝土结构的耐久性，而且从全寿命周期角度考虑还具有良好的经济性，因而其在沿海等腐蚀环境的混凝土结构中有着广泛应用前景。混凝土结构总是承受着各种荷载，掌握应力应变对混凝土结构中不锈钢钢筋耐蚀性能的影响具有重要科学意义。本项目针对混凝土环境中应力对不锈钢早期腐蚀特征的影响这一关键科学问题，以奥氏体不锈钢为对象，研究其在应力作用下的钝化过程；其在应力作用下钝化膜的破损和再钝化过程；以及应力作用下其孔蚀萌生特征。综合基体微观结构的演变和不锈钢钝化性能的变化，阐明应力影响混凝土环境中不锈钢钝化性能的机理，明确钝化膜在应力作用下的破损机制，揭示应力影响不锈钢孔蚀萌生的规律。研究成果可指导混凝土结构中不锈钢孔蚀孕育周期的估算，为不锈钢混凝土结构的寿命预测提供线索，并为预应力不锈钢钢筋的应力设计提供理论参考。

中文关键词： 应力；混凝土；不锈钢钢筋；钝化；孔蚀

英文摘要： Corrosion of reinforcing steel is the major problem that affects the durability of reinforced concrete structures. The structure used stainless steel reinforcing bar showed exceptional performance for corrosion mitigation. Moreover, it seems to be an economically profitable alternative for the concrete structures exposed to aggressive environments. Engineering concrete structures always suffered various kinds of loads. Thus, it is important to clarify the effects of stress on corrosion behaviour of stainless steel in concrete structures. In this project, the key scientific problem that the influence of stress on initial corrosion behaviour of stainless steel will be investigated. With austenitic stainless steel as experimental materials, the formation process of passive films on loaded samples in cement extract will be studied. The breakage of the passive film on stainless steel under stress will also be investigated. In addition, pit initiation characteristic of stainless steel under stress will be studied. Coupled with microstructures analysis of substrate and passive film, the mechanism of stress affects passivation and pit initiation of stainless steel will be discussed. The breakage mechanism of passive film under different kinds of stress will be suggested. The results may provide references for life predi

英文关键词： Stress；concrete；stainless steel rebar；passivation；pitting corrosion