摘要：双相不锈钢已经在各个领域内逐步代替奥氏体不锈钢的使用。其中2205双相不锈钢因其本身优异的综合力学性能、较低的腐蚀敏感性和应用成本，成为目前全球范围内应用最广泛的双相不锈钢材料,但这种材料仍然处于发展阶段并且有非常大的发展空间。氢是不锈钢材料在工作环境中经常接触到的物质，所以本课题研究氢对2205双相不锈钢钝化膜破裂和点蚀萌生具有重要意义。

本课题主要采用控制变量法，分别控制充氢电流密度和充氢时间研究氢对双相不锈钢钝化膜和耐点蚀性能的影响。具体方法是将预充氢后的试样进行钝化处理，然后采用电化学阻抗法、Mott-Schottky曲线法和动电位扫描法对钝化膜进行测试。通过分析电化学测试后得到的图谱，研究氢对钝化膜的半导体性质和对基体材料保护性能的影响。本课题还采用了超景深三维显微系统和钨灯丝扫描电子显微镜分别对预充氢和阳极极化后的钝化膜表面进行了观察，研究钝化膜的完整性、致密度和腐蚀形貌等。最后发现：充氢电流密度增大和时间的延长，阻碍了2205双相不锈钢表面钝化膜的生成过程。因此减小了钝化膜的电阻，增大了钝化膜中的氧空位浓度，使钝化膜中的缺陷变多，导电性提高，最终使钝化膜易于破裂在NaCl溶液中发生点蚀。

关键词：2205双相不锈钢；钝化膜；点蚀；充氢；电化学

Abstract：Duplex stainless steel has been gradually used in various fields instead of austenitic stainless steel.2205 duplex stainless steel because of its excellent overall mechanical properties, lower corrosion sensitivity and low cost of use, has become the world's most widely used duplex stainless steel. Hydrogen is a material that is often exposed to stainless steel materials in the working environment. Therefore, it is important to study the influences of hydrogen on the cracking and pitting initiation of 2205 duplex stainless steel.

In this paper, the effect of hydrogen on the passivation film and pitting corrosion resistance of duplex stainless steel was studied by controlling the variable current method and the hydrogen charging time.The method is that the pre-hydrogenated sample is passivated, and then the passivation film is tested by electrochemical impedance method, Mott-Schottky curve method and dynamic potential scanning method.The influence of hydrogen on the properties of the passivation film and the protective properties of the matrix was studied by analyzing the spectra obtained after the electrochemical test. In this paper, the surface of the passivation film after pre-hydrogenation and anodic polarization was observed by using the super-depth-depth three-dimensional microscopy system and the tungsten filament scanning electron microscope. The integrity, density and corrosion morphology of the passivation film were studied Wait. Finally, it was found that the increase of hydrogen current density and the prolongation of time hindered the formation process of 2205 duplex stainless steel surface passivation film. So that the resistance of the passivation film is reduced, the oxygen vacancy concentration in the passivation film is increased, the defects in the passivation film are increased, the conductivity is improved, and the passivation film is easily cracked in the NaCl solution.

Keywords:  2205  duplex  stainless  steel ； passivation  film ； pitting  corrosion ；hydrogenation；electrochemistry

目录

第一章绪论1

1.1前言..1

1.2双相不锈钢研究现状2

1.2.1双相不锈钢的发展历程..2

1.2.2双相不锈钢的分类2

1.3双相不锈钢特点与性能.3

1.3.1双相不锈钢的特点4

1.3.2双相不锈钢的应用5

1.3.3不锈钢钝化膜的介绍.6

1.4氢对不锈钢的影响..8