采用电化学动电位再活化法(EPR)、动电位极化和交流阻抗测试方法(EIS)研究2507双相不锈钢(SAF2507)在5g/L NaClO溶液中的晶间腐蚀和点腐蚀行为,并采用X射线光电子能谱(XPS)研究SAF2507腐蚀后表面形成的钝化膜组成。结果表明:SAF2507的再活化率Ra为0.68%,具有良好的耐晶间腐蚀性能;动电位极化和EIS的测试结果表明:SAF2507极化后能够发生自钝化现象,钝化区间为-0.5-0.6V;电荷传递电阻为1.389×10^4Ω·cm^2,说明其具有较强的耐点腐蚀性能。XPS研究表明SAF2507在5g/L NaClO溶液中钝化膜主要成分为Cr,Fe等氧化物和氢氧型化合物。同时进一步探讨了SAF2507的腐蚀机理。
Electrochemical potentiodynamic reactivation(EPR),potentiodynamic polarization curve and electrochemical impedance spectroscopy(EIS)methods were applied to investigate the intergranular corrosion and the pitting corrosion behaviors of 2507 duplex stainless steel(SAF2507),and the composition of the passive film formed on the corrosive surface of SAF2507 was studied by using the X-ray photoelectron spectrometer(XPS)analysis.The results show that the reactivation rate(Ra)of SAF2507 is 0.68%,which exhibits good intergranular corrosion resistance.The results of potentiodynamic polarization curve,and EIS show that the surface of SAF2507 can engender passivation phenomenon after polarization,the passivation range is-0.5-0.6V,and the charge transfer resistance is1.389×10^4Ω·cm^2,which shows better pitting corrosion resistance.XPS demonstrates that the composition of the passive film in 5g/L NaClO solution is mainly composed of oxides and hydrogen oxygen compounds of Cr and Fe.Meanwhile,the corrosion mechanism of SAF2507 was further explored.