通过电化学测试、慢应变速率拉伸试验（SSRT）并结合扫描电镜（SEM）分析了TC4-0.55% Fe合金在模拟海水中的应力腐蚀开裂（SCC）行为，揭示了应变速率（3.3×10^-6 s^-1~10.0×10^-6 s^-1）对合金SCC行为的影响。结果表明：合金在模拟海水中具有应力腐蚀开裂敏感性；当应变速率为5.0×10^-6 s^-1时，合金在模拟海水中的断口中心区域形貌以细小扁平韧窝为主，塑形变形不充分，呈现出脆性特征，表现出最高的应力腐蚀敏感性。当应变速率大于6.6×10^-6 s^-1时，合金的断口由小而浅的韧窝向大而深的韧窝过渡，由此说明，高应变速率下，拉应力作用使试样迅速断裂，合金应力腐蚀敏感性较小，断口处有明显韧窝，表现出典型的韧性断裂特征。

The stress corrosion cracking (SCC) performance of TC4-0.55% Fe alloy in simulated seawater solution was investigated by electrochemical measurements, slow strain rate test (SSRT) and scanning electron microscopy (SEM). The effect of strain rate (changed from 3.3×10^-6 s^-1-10.0×10^-6 s^-1) on SCC behavior of the alloy was revealed. The results showed that TC4-0.55% Fe alloy possessed the maximum SCC susceptibility at the strain rate of 5.0×10^-6 s^-1 in the simulated seawater solution, the fracture surface was dominated by flattened dimples, with obvious tearing edges between the dimples, and the quasi-cleavage fracture surface appeared in the middle region of the fracture. When the strain rate was higher than 6.6×10^-6 s^-1, the fracture surface was changed from small and shallow dimples to large and deep dimples. Therefore, tensile stress made the specimen fractured rapidly at high strain rates, and the SCC susceptibility of the alloy was very small, its fracture showed typical ductile fracture with appreciable dimples.