海洋大气环境Cu/Ni协同作用对低合金钢耐蚀性影响

Effect of Synergistic Action of Cu/Ni on Corrosion Resistance of Low Alloy Steel in a Simulated Tropical Marine Atmosphere

通过模拟严苛热带海洋大气环境的室内喷淋加速实验,研究了Cu/Ni协同作用对低合金钢的腐蚀速率及锈层形貌、成分的影响,测试3种合金试样在0.5%(质量分数) NaCl溶液中的电化学阻抗及线性极化曲线。结果表明,随着Cu、Ni含量的提高,钢材在喷淋实验下生成的锈层逐渐变薄且致密,同时Cu在锈层的富集作用阻碍了Cl-入侵。Cu、Ni两种元素在一定程度上提高了基体金属溶解反应的电荷转移电阻(Rt)及极化电阻,加速了保护性锈层的形成并从阳极电化学反应抑制作用上提高了锈层的保护性。

The effect of synergistic action of Cu and Ni on corrosion rate, morphology and composition of the rust formed on three low alloy steels with different contents of Cu and Ni was studied via indoor spray acceleration tests, aiming to simulate the harsh tropical marine atmosphere. Meanwhile, electrochemical impedance spectroscopy(EIS) and linear polarization tests for the three steels were also carried out in 0.5%(mass fraction) NaCl solution. The results show that with the increase of Cu-and Ni-content, the rust layer formed on the steels subjected to spraying test becomes gradually thinner and denser,and the enrichment of Cu in the rust layer mitigates the invasion of Cl-. The charge transfers resistance(Rt) and polarization resistance of the metal dissolution reaction were increased to some extent by the synergistic effect of two elements of Cu and Ni, which accelerated the formation and enhanced the protectiveness of the rust layer through inhibiting the anodic electrochemical reaction.