采用线性极化电阻、塔菲尔曲线法和电化学阻抗谱(EIS)技术研究了316L不锈钢(316LSS)在不同电导率海水和NaCl溶液中的电化学腐蚀行为.结果表明,316LSS在两种腐蚀介质中的极化电阻(Rp)、自腐蚀电位(Ecorr)和点蚀电位(Eb100)均随电导率的升高而降低.同时EIS显示电导率对电荷转移电阻(R1)影响不大,而对膜电阻(R2)影响较大,说明随电导率的变化,腐蚀介质中侵蚀离子主要影响316LSS的钝化膜的稳定性.316LSS在NaCl溶液中的R2、Ecorr、Eb100值比在相同电导率海水中分别最大减少了6.5×105Ω· cm2、54mY和143mY,说明在电导率相同时,316LSS更易在NaCl溶液中发生腐蚀.因此,在海水源热泵系统应用研究中,应该尽量采用实际海水作为腐蚀介质.%The electrochemistry corrosion behaviors of 316 L stainless steel in different electric conductivities of seawater and NaCl solution were investigated by Linear polarization, variation of potential dynamic polarization curves and electrochemical impedance spectroscopy(EIS). The results showed that the polarization resistance (Rp), corrosion potential (Ecorr) and pitting potential (Eb100) of 316LSS reduced with the increase of electric conductivities in corrosion mediums. EIS showed that the electric conductivity had a little impact on the charge-transfer resistance (R1), while had greater impact on the membrane resistance (R2). With the change of conductivity, erosive ions of corrosion mediums mainly impacted the stability of the passive film of 316LSS. In the NaCl solution, R2, Ecorr and Eb100 of 316LSS reduced 6. 5×105Ω·cm2, 54mV and 143mV, respectively, comparing with that in seawater with the same conductivity. This showed that under the same conductivity, the 316LSS corrosion test in NaCl solution corroded more serious than that in the actual seawater. In the studies of the Seawater Source Heat Pump system application, we should use the natural seawater as the corrosion mediums.
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