氯离子对2205双相不锈钢抗氢氟酸腐蚀性能的影响

Effect of Chloride Ion on Corrosion Resistance of 2205 Duplex Stainless Steel in Hydrofluoric Acid

采用浸泡失重、动电位极化和电化学阻抗等方法,研究了2205双相不锈钢在含有不同浓度氯化钠(NaCl)的氢氟酸(HF)介质中的腐蚀行为。结果表明,当HF溶液中加入浓度为0.015~0.030mol/L的NaCl时,随着NaCl浓度的逐渐增加,2205双相不锈钢在该溶液中的腐蚀电位逐渐变负,自腐蚀电流密度逐渐增大,平均腐蚀速率逐渐升高。这主要是因为NaCl降低HF溶液的pH所致。

The corrosion behavior of 2205 duplex stainless steel(DSS)in hydrofluoric acid(HF)was affected by the chlorine ion.The methods including immersion,potentiodynamic polarization and electrochemical impedance spectra(EIS)were used to understand the effect.The results showed that while the NaCl concentration was added into HF solution from 0.015 mol/L to 0.030 mol/L,the corrosion potential got more positive,and the corrosion current density and average corrosion rate increased with the increasing NaCl content.It was because that NaCl decreased the pH of HF solution.