目的 探究TA2-Q235在模拟海水溶液中的电偶腐蚀、缝隙腐蚀及电偶缝隙耦合作用机制，为钛钢复合板在海洋工程结构中的应用设计提供理论指导，提升工程构件使用寿命。方法 通过测量极化曲线、阴阳极开路电位，探究Q235和TA2在电偶腐蚀、缝隙腐蚀及电偶缝隙耦合时阴阳极的极化行为。通过电偶腐蚀测量仪，测量电偶电流，通过腐蚀质量损失，表征阳极金属溶解速率。利用SEM观察微观腐蚀形貌，评价阳极金属腐蚀程度及表面腐蚀产物膜状态。结果 腐蚀介质为中性3.5% NaCl时，单独Q235的自腐蚀电流密度为35.5 μA/cm²，呈现均匀腐蚀形貌。Q235与TA2偶接时，耦合电位接近Q235自腐蚀电位，测得平均电偶电流密度为40.5 μA/cm²，TA2对Q235阳极溶解加速效应较弱。Q235缝隙样品的缝隙内外不存在电位差，缝内因为供氧不足，阴极反应受到抑制，腐蚀程度小于缝外;TA2-Q235电偶缝隙耦合时，缝内Q235的腐蚀速率低于自腐蚀速率。结论 TA2-Q235电偶与缝隙耦合时，缝隙内缺氧对Q235阴极反应的抑制效应大于TA2电偶对Q235阳极反应的促进效应，使缝内Q235的腐蚀速率低于自腐蚀速率。

This work aims to study the galvanic corrosion, crevice corrosion and synergetic effect of TA2-Q235 couple in simulated seawater solution, which provides theoretical guidance for application of titanium steel composite plate in marine engineering structures and improves the service life of components. The anodic and cathodic polarization behavior of TA2 and Q235 during different corrosion forms were investigated through polarization curves and potential. The anodic dissolution rate of Q235 was measured by electrochemical workstation and corrosion mass loss. The corrosion degree of anodic metal and surface morphology of corrosion product were observed by optical microscope and SEM. The results indicated self-corrosion current density of Q235 in 3.5% NaCl solution was 35.5 μA/cm2 and it showed typical uniform corrosion. The coupled potential was close to the corrosion potential of Q235 and the average galvanic corrosion density of galvanic couple was 40.5 μA/cm2, which indicates the acceleration effect by TA2 on anodic dissolution of Q235 was light. There was no potential difference inside and outside crevice of Q235, which causes no galvanic current in the circuit. The cathodic reaction inside crevice was inhibited due to insufficient oxygen supply, resulting in less corrosion degree inside crevice than outside crevice. The morphology outside crevice was close to self-corrosion of Q235. The corrosion rate inside crevice of Q235 was lower than its self-corrosion under the synergetic effect of galvanic and crevice of TA2-Q235. The inhibition effect of oxygen depletion inside crevice on cathodic reaction of Q235 was stronger than the acceleration effect of TA2 galvanic effect on anodic reaction of Q235, which cause corrosion rate inside crevice of Q235 was lower than its self-corrosion.