关键词: 碳钢, 缝隙腐蚀, 溶液化学, 阳极极化

Abstract: A self_made wedge_shaped simulated crevice apparatus was designed to investigate the solution chemistry in crevice of carbon steel and its anodic polarization behavior. For carbon steel with 3.5%(wt) NaCl , the change and the distribution of electrode potential , concentration of Cl- and pH value of solution in the crevice, and the current density of metal in the crevice were measured respectively under various conditions of anodic polarization. The results showed that without polarization the metal about 2 cm away from the opening of the crevice was attacked preferentially because of its lowest free corrosion potential. The anodic polarization promoted the corrosion in the crevice, and increased H+ and Cl- concentrated in the crevice. The metal at the mouth of crevice was corroded more seriously because of the polarization, but the metal at the deep of crevice was protected by the film of salt.