HAl77-2黄铜在流动海水中的电化学行为

ELECTROCHEMICAL BEHAVIOR OF HAl77-2 BRASS IN FLOWING SEAWATER

利用旋转圆环电极、电化学阻抗谱(EIS)和线性极化方法研究了HAl77-2黄铜在流动海水中的电化学行为。结果表明,HAl77-2黄铜在不同流速海水中呈现不同的EIS特征,静止海水中EIS呈现扩散影响的特征;流速<4m/s的海水中,EIS大体表现为电荷传递控制的特征;流速≥4.5m/s时,EIS谱线低频部分呈现感抗弧。HAl77-2黄铜的腐蚀速率受海水流速的影响,流速≤2m/s时,腐蚀速率随着流速的增大基本上呈线性递增;流速在2m/s^4m/s范围内,腐蚀速率的变化较小;流速≥4.5m/s时,试样出现点蚀,且随着流速的增加腐蚀速率又迅速增大。

The electrochemical behavior of HAl77-2 brass alloy in flowing seawater was studied by using rotating ring electrode. Electrochemical impedance spectroscope （EIS） and linear polarization methods were carried out. The results show that the EIS of HAl77-2 brass alloy in seawater at different flow velocities presents different characteristics ：The EIS presents characteristics of diffusion control in still water.The EIS characteristics is charge transfer control when the flow velocity is lower than 4 m/s.Inductive reactance arc occurs when the flow velocity is higher than 4.5 m/s. The corrosion rate of HAl77-2 brass is influenced by the flow velocity. The corrosion rate increases linearly ,wnen the flow velocity is lower than 2 m/s.As the flow velocity increases from 2 m/s to 4 m/s, the corrosion rate increases insignificantly.Pitting occurs when the flow velocity is higher than 4.5 m/s,consequently the corrosion rate increases sharply.