苏宏艺, 魏世丞, 梁义, 王玉江, 王博, 袁悦, 徐滨士. 静水压与溶解氧耦合作用对低合金高强钢腐蚀电化学行为的影响[J]. 工程科学学报, 2019, 41(8): 1029-1036. DOI: 10.13374/j.issn2095-9389.2019.08.008
引用本文: 苏宏艺, 魏世丞, 梁义, 王玉江, 王博, 袁悦, 徐滨士. 静水压与溶解氧耦合作用对低合金高强钢腐蚀电化学行为的影响[J]. 工程科学学报, 2019, 41(8): 1029-1036. DOI: 10.13374/j.issn2095-9389.2019.08.008
SU Hong-yi, WEI Shi-cheng, LIANG Yi, WANG Yu-jiang, WANG Bo, YUAN Yue, XU Bin-shi. Combined effect of hydrostatic pressure and dissolved oxygen on the electrochemical behavior of low-alloy high-strength steel[J]. Chinese Journal of Engineering, 2019, 41(8): 1029-1036. DOI: 10.13374/j.issn2095-9389.2019.08.008
Citation: SU Hong-yi, WEI Shi-cheng, LIANG Yi, WANG Yu-jiang, WANG Bo, YUAN Yue, XU Bin-shi. Combined effect of hydrostatic pressure and dissolved oxygen on the electrochemical behavior of low-alloy high-strength steel[J]. Chinese Journal of Engineering, 2019, 41(8): 1029-1036. DOI: 10.13374/j.issn2095-9389.2019.08.008

静水压与溶解氧耦合作用对低合金高强钢腐蚀电化学行为的影响

Combined effect of hydrostatic pressure and dissolved oxygen on the electrochemical behavior of low-alloy high-strength steel

  • 摘要: 采用动电位极化测试和扫描电子显微镜/能谱仪表征, 通过理想动电位极化曲线分析方法和微观腐蚀形貌观察研究了静水压与溶解氧耦合作用对低合金高强钢在质量分数为3.5% NaCl溶液中腐蚀电化学行为的影响. 结果表明: 随着静水压和溶解氧溶度的同时增大, 腐蚀电位先增高而后逐渐降低, 腐蚀电流呈非线性增长; 静水压与溶解氧在腐蚀过程中存在相互竞争抑制关系, 在静水压与溶解氧同时增长过程中, 溶解氧首先促进阴极反应过程并抑制阳极反应过程, 而后静水压逐渐加速阳极过程并对阴极反应过程有一定的抑制作用; 静水压与溶解氧耦合作用加速了腐蚀产物膜的生长, 增加了低合金高强钢表面点蚀坑的数量和生长尺寸.

     

    Abstract: With the development of marine industry, the performances of metal materials in marine environment have gathered much attention of scientists. Seawater, as a Cl--containing electrolyte, degrades the properties of steel structures and limits their service life due to its erosion to steel surface. The corrosion phenomena of low-alloy high-strength steels in surface seawater are well known but not sufficiently understood in deep-sea environment. The effect of hydrostatic pressure on the corrosion behavior of low-alloy steels is a focus in this aspect. However, the results from the laboratory study cannot well illustrate the ones from the field test, because some factors change simultaneously with the increase of ocean depth. Therefore, it is necessary to study the corrosion behaviors of steels in a multi-factor coupled environment. In this report, the combined effect of hydrostatic pressure and dissolved oxygen on the electrochemical behavior of low-alloy high-strength steel in 3.5% (mass fraction) NaCl solution was investigated using potentiodynamic polarization tests and scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS) measurements. The results show that the corrosion potential increases at first and then decreases with the increase of both hydrostatic pressure and dissolved oxygen. The corrosion current density exhibits a nonlinear increasing tendency with the increase of these two factors. The ideal polarization curve method was used to analyze the interaction of hydrostatic pressure and dissolved oxygen in the corrosion process. The results indicate that there is a competitive inhibition relationship between hydrostatic pressure and dissolved oxygen. With the increase of both hydrostatic pressure and dissolved oxygen, dissolved oxygen first accelerates the cathodic reaction process and inhibits the anodic reaction process. Afterwards, hydrostatic pressure starts accelerating the anodic reaction rate and inhibits the acceleration of the cathodic process caused by dissolved oxygen. The corrosion films on the steel surface significantly inhibit the acceleration to corrosion process given by the combined effect of hydrostatic pressure and dissolved oxygen. Moreover, these two combined factors encourage the growth of corrosion films and increase the number and sizes of corrosion pits forming on the steel surface.

     

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