氯离子浓度与酸度对TTS443铁素体不锈钢耐蚀性能的影响

Corrosion Behavior of TTS443 Ferrite Stainless Steel in NaCl or HCl Solution

采用极化曲线、电化学阻抗谱(EIS)等测试方法,研究了Cl-浓度与酸度大小对TTS443不锈钢腐蚀速率与耐点蚀性的影响,并对比了同等条件下304不锈钢的腐蚀情况。结果表明,随着Cl-浓度的增大,点蚀电位(Eb)先负移后正移,自腐蚀电流(Icorr)先增大后减小,Cl-浓度为12%时腐蚀速率最快;HCl溶液中,随酸度的增大,TTS443不锈钢的腐蚀速率增大,Eb值负移。同等Cl-含量的中性溶液中,TTS443不锈钢腐蚀速率比304不锈钢慢,但耐点蚀性能却较弱;同等酸性条件下,与304不锈钢比较,TTS443不锈钢腐蚀速率较快,耐点蚀能力较弱。

The corrosion behavior especially pitting resistance of TTS443 stainless steel, in comparison with 304 stainless steel, was studied by means of polarization curves and electrochemical impedance spectroscopy （EIS）, in NaC1 and HC1 solutions respectively. The results showed that, with the increase of mass fraction of CI-, the pitting potential （Eo） of TTS443 stainless steel decrease first and then increase ,and corrosion current （Low） increase first and then decrease, in 12%NaC1 solution, while the corrosion rate was the highest. In solutions with the same concentrati on of CI the corrosion rate of TTS443 stainless steel was slower than 304, but the pitting corrosion resistance is weaker. However in HC1 solution, with the increase of concentration of HC1, the corrosion rate was increased, the value of ~ reduced. In solutions with the same acidity, the corrosion rate of TTS443 stainless steel was faster, and the pitting corrosion resistance was weaker rather than 304 stainless steel.