静水压力对金属腐蚀热力学及动力学的影响  

Influence of Hydrostatic Pressure on the Thermodynamics and Kinetics of Metal Corrosion

作　　者：马荣耀 赵林[1] 王长罡[1] 穆鑫[1] 魏欣[1] 董俊华[1] 柯伟[1] MA Rongyao;ZgAO Lin;WANG Changgang;MU Xin;WEI Xin;DONG Junhuai;KE Wei(Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;University of Chinese Academy of Sciences, Beijing 100049, China)

机构地区：[1]中国科学院金属研究所,沈阳110016 [2]中国科学院大学,北京100049

出　　处：《金属学报》2019年第2期281-290,共10页Acta Metallurgica Sinica

基　　金：国家重点研发计划项目No.2017YFB0702302;国家自然科学基金项目Nos.51671200;51501204~~

摘　　要：以热力学和动力学为基础,分析了静水压力对电极反应中材料的活度、环境中离子的活度、气体的溶解度、活度或逸度的影响,讨论了静水压力对海水环境中的pH值及化学平衡的作用,给出了静水压力与电极反应平衡电极电位和交换电流密度的关系式,并建立了静水压力影响活性金属腐蚀行为的理论模型。研究表明,静水压力可提高材料、环境中离子及溶解气体的活度,且这与其偏摩尔体积密切相关;静水压力对异相材料的活度差异具有放大效应,异相材料的偏摩尔体积相差越大,活度的差异越明显。升高静水压力可降低金属Fe和Al阳极溶解反应的平衡电极电位,同时降低其交换电流密度;升高静水压力可提高吸氧反应的平衡电极电位,降低其交换电流密度;升高静水压力可降低析氢反应的平衡电极电位,增大其交换电流密度。In recent years, researches on deep sea corrosion have attracted much attention of many researchers. The high hydrostatic pressure is a distinctive feature of deep-sea environment. The hydrostatic pressure affects the corrosive behavior of metallic materials by modifying the composition, structure and compactness of corrosion products, changing the polarization processes of cathode electrode and anode electrode, altering pitting nucleation rate and growth rate, impacting on chemical reaction rate and equilibrium constant, and varying hydrogen diffusion rate and coverage. However, in essence, the influence of hydrostatic pressure on the corrosion behavior of different metal materials is the manifestation of the thermodynamic and kinetic parameters of the corrosion electrode process caused by hydrostatic pressure. At present, the mechanism of effect of hydrostatic pressure on the thermodynamics and kinetics of corroding electrode processes is unclear yet. In addition, the concerns about the effects of hydrostatic pressure on the chemical properties of materials and seawater are comparatively low. Based on thermodynamics and kinetics, the effects of hydrostatic pressure on the activities of electrode material and ions in environment, including on the solubility, fugacity or activity of gases in environment are analyzed. The influence of hydrostatic pressure on pH value and chemical equilibrium is also discussed. The relationships between hydrostatic pressure and equilibrium electrode potential, as well as the exchange current density, are analyzed. The theoretical model of the effect of hydrostatic pressure on the corrosion behavior of active metals is established. The studies have shown that hydrostatic pressure would increase the activities of materials, ions and dissolved gas in environments, and this is closely related to their partial molar volume. The hydrostatic pressure would magnify the difference in the activity of heterogeneous materials. The larger the partial molar volume difference of the heterogeneous

关 键 词：静水压力 活度 逸度 溶解度 平衡电极电位 交换电流密度 

分 类 号：O646.6[理学—物理化学] TG171[理学—化学]