海底海缆镀锌钢丝铠装层在模拟海水中腐蚀研究

Study on Corrosion of Galvanized Steel Wire Armor Layer of Submarine Cable in Simulated Seawater

【目的】近年来风力发电、海洋油气的开发、跨国电网及通信的互联,使得海底电缆/海底光电复合缆需求大大增加。但海缆修复成本较高,因此提高海缆的使用寿命有一定的研究价值。对海缆铠装层镀锌钢丝在海水中的腐蚀情况进行研究,可以了解海水中各离子对其的腐蚀作用。【方法】选择某公司海底电缆铠装层镀锌钢丝,三个平行试样在常温条件下分别在只含Cl^(-)、SO_(4)^(2-)、HCO_(3)^(-)离子的溶液及三种离子的混合溶液中即模拟海水,使用CS2350H型电化学工作站进行测试,先做试样的开路电位,然后做电化学交流阻抗谱,最后做动电位极化。【结果】当开路电位稳定后,所做的交流阻抗谱得出的数据反映在模拟海水溶液中,镀锌钢丝腐蚀最快,在只含HCO_(3)^(-)离子的溶液中腐蚀最慢。通过极化曲线试验中腐蚀电流密度的比较可知,试样在模拟海水溶液中发生的腐蚀最严重。【结论】由试验结果得出,模拟海水溶液中SO_(4)^(2-)离子对镀锌钢丝影响最大。本试验只考虑三种离子,实际海水中会有其他离子及微生物等会对海缆有腐蚀作用,今后可以进一步研究。

[Purposes]In recent years,with the development of wind power,offshore oil and gas,cross border power grids,and the interconnection of communications,the demand of submarine cable/submarine photoelectric composite cable is greatly increased.However,the cost of cable repair is high,so to improve the life of cable research has a certain significance.The Corrosion of galvanized steel wire for submarine cable armor layer in seawater was studied.[Methods]In this paper,three parallel samples of galvanized steel wire for submarine cable armor were selected from a company,and were simulated as seawater in the solution containing only Cl^(-)、SO_(4)^(2-)、HCO_(3)^(-)and the mixed solution of three ions at normal temperature.Using of CS2350H electrochemical workstation to test,this study first makes the open-circuit potential of the sample,then does electrochemical impedance spectroscopy,and finally performs potential polarization.[Findings]When the open-circuit potential is stable,the corrosion rate of galvanized steel wire is the fastest in simulated seawater solution and the slowest in HCO_(3)^(-)solution.Through the comparison of the corrosion current density in the polarization curve test,it can be known that the most serious corrosion occurs in the simulated seawater solution.[Conclusions]The results show that SO_(4)^(2-)has the greatest effect on galvanized steel wire in simulated seawater solution.Only three kinds of ions are considered in this experiment.There are other ions in seawater and other factors,such as microorganisms,which can corrode the cable.