中文摘要：

应用楔型缝隙模型研究了腐蚀介质中Cl^-浓度对X70管线钢缝隙腐蚀的影响规律．实验结果表明：在自然腐蚀状态下，当缝口宽度为0．15mm以及实验周期为120h时，随着缝外腐蚀介质中Cl^-浓度（c^mcl）的提高，从缝口到缝底缝内溶液中的Cl^-浓度（c^ccl）逐渐增加，pH值逐渐降低，试样的电极电位也逐渐降低，表明随着腐蚀介质中c^mcl-的增加，XTO管线钢的缝隙腐蚀倾向逐渐增强．

英文摘要：

The influence of Cl^- concentration in corrosion medium to crevice corrosion of X70 pipeline steel was investigated by wedge-type crevice model. The experimental results show that under natural corrosion condition, as the crevice opening thickness is 0.15 mm and the test periodic is 120 h, with increase of the Cl^- concentration （c^mcl-） in corrosion medium outside the crevice the Cl^- concentration （cOol） in the crevice solution from the opening to the bottom gradually increases, the pH value in the crevice solution and the electrode potential of X70 steel samples from the opening to the bottom in the crevice gradually decrease, which indicated that crevice corrosion tendency of X70 steel increases with increase of the Cl^- concentration （c^mcl-） in corrosion medium outside the crevice.