钢表面阻变性保护膜的设计、制备与耐蚀机制研究

The corrosion resistance of carbon steel and low alloy corrosion resistant steel in atmosphere and marine environments is highly depended on the rust layer formed on steel surface. Based on the composition and structure characteristics of rust layer, the concept of resistive switching protection film is introduced in the protection of steel because of its structure characteristic and resistive switching mechanism. By considering the beneficial effect of Mg, Zn, Cr and Al elements in the corrosion resistance of steel, the resistive switching protection films with single composition of MgxZn1-xO, Zn1-xCrxO, Zn1-xAlxO and heterostructure of NiO/ZnO, CeO2/ZnO are designed and prepared on steel surface by using sol-gel, hydrothermal and painting technology, and the corrosion resistance of films could be improved by controlling the concentration of defect and the height of electron barrier in the film. And then the influence of composition, structure, defect concentration and ion selective ability on the resistive switching and healing behavior of films are investigated and analyzed by using modern surface analytical apparatus, electrochemical techniques and theoretical simulation method, and the corrosion mechanism of resistive switching protection films are deduced and concluded. Finally, the long-term corrosion behavior and evolution process of resistive switching protection films in atmosphere and marine environments are determined, and the composition, structure and preparation conditions of films are optimized. After that, the relationship among the corrosion resistance, composition and structure of films are built. All these results are very helpful to the practical application of resistive switching protection films on the steel in the atmosphere and marine field, and have an important influence on the improvement of corrosion resistance and service life of steel.

以提高碳钢、低合金耐蚀钢在大气和海水中的耐蚀性为研究对象，在分析保护性锈层成分和结构特点基础上，依据阻变薄膜的特征与阻变机理，并考虑到Mg、Zn、Cr、Al等在提高耐蚀性中的作用，通过溶胶-凝胶、水热沉积和涂覆等方法在钢表面设计制备出MgxZn1-xO、Zn1-xCrxO、Zn1-xAlxO等单一种类阻变性保护膜、及NiO/ZnO、CeO2/ZnO等异质结型阻变性保护膜，进而通过薄膜中缺陷浓度、电子势垒高度等的调控提高钢的耐蚀能力。利用现代表面分析、电化学测试和理论模拟等方法研究阻变性保护膜的成分、结构、缺陷浓度、离子选择性对材料阻变行为、修复愈合规律的影响，揭示其耐蚀机制。最后，通过探明阻变性保护膜的长期腐蚀行为和演化规律，优化阻变性保护膜的成分、结构与制备工艺，从而建立起阻变性保护膜的耐蚀性能与其成分、结构间的内在联系，促进阻变性保护膜在钢铁构件中的工程应用，以提升钢铁构件的服役寿命。

针对钢铁材料在大气和海水中的腐蚀问题，项目在分析钢表面保护性锈层成分和结构特点基础上，依据阻变薄膜的结构特征与阻变机理，并考虑到Mg、Zn、Cr、Al等元素在提高耐蚀性中的作用，通过溶胶-凝胶、水热沉积、电沉积与旋涂等方法成功地在钢基体表面设计制备出ZnO（一元金属氧化物）、MgxZn1-xO、Zn1-xCrxO、Zn1-xAlxO（二元金属氧化物）、及CeO2/ZnO、NiO/ZnO（复合金属氧化物）等阻变性保护膜。利用SEM、XRD、FTIR、XPS等现代表面分析技术对阻变薄膜的形貌、成分、结构和缺陷特征进行了表征；并通过电化学测试技术对阻变薄膜的缺陷浓度、耐蚀性能、阻变特性进行了系统的研究；在此基础上，还利用计算机模拟方法对阻变薄膜的空位形成能、结合能与差分电荷密度等参数进行了分析。从而建立起阻变性保护膜的耐蚀性能、阻变行为与其成分、结构间的内在联系，优化了阻变薄膜的制备工艺和耐蚀性能；提出了阻变薄膜的耐蚀机制、阻变机制与修复愈合方法。这些研究结果，对开发新型耐蚀保护方法、提升钢铁构件的耐蚀性能和服役寿命、促进阻变性保护膜在钢铁工程构件防护中的应用具有重要的意义。