绿色缓蚀剂SDDTC对AZ31B镁合金的缓蚀作用及吸附行为

Corrosion Inhibition and Adsorption Behavior of Green Corrosion Inhibitor SDDTC on AZ31B Mg-alloy

采用极化曲线、电化学阻抗谱、红外光谱及扫描电镜等方法研究了二乙基二硫代氨基甲酸钠(SDDTC)对AZ31B镁合金在3.5%(质量分数)NaCl溶液中的缓蚀作用及吸附行为。结果表明,SDDTC能有效抑制AZ31B镁合金在NaCl介质中的腐蚀,属阴极抑制为主的混合型缓蚀剂。当SDDTC浓度为5 mmol·L^(-1)时,缓蚀效果最好。SDDTC在AZ31B镁合金表面发生物理吸附,符合Langmuir吸附模型。吸附在表面的SDDTC形成较为致密的保护膜,有效抑制了AZ31B镁合金的腐蚀。

The corrosion inhibition and adsorption behavior of sodium diethyldithiocarbamate（SDDTC） on AZ31B Mg-alloy in 3.5%（mass fraction） Na Cl solution were investigated by means of potentiodynamic polarization measurement, electrochemical impedance spectroscopy（EIS）, Fourier transform infrared spectroscopy（FT-IR） and scanning electron microscopy（SEM）. Results showed that SDDTC could inhibit effectively the corrosion for AZ31B Mg-alloy in Na Cl solution, and acted as a mixed-type inhibitor with predominant control of the cathodic reaction. When the concentration of SDDTC was 5 mmol·L^（-1）, the inhibition efficiency was the best. The physical adsorption of SDDTC on the AZ31B Mg-alloy surface obeyed the Langmuir adsorption isotherm. While SDDTC adsorbed on the surface of Mg-alloy forms a much compact protective film, effectively inhibiting the corrosion of AZ31B Mg-alloy.