抗坏血酸缓蚀剂对Q235钢耐蚀性能的影响

Effect of ascorbic acid inhibitor on corrosion resistance of Q235 steel

采用失重法研究L-抗坏血酸缓蚀剂在生产二苯甲酰甲烷的废水中对Q235钢缓蚀性能的影响。用电化学法研究缓蚀剂膜的自腐蚀电流密度、极化腐蚀电流密度和极化阻抗。用SEM研究存在与不存在缓蚀剂膜的Q235钢在极化腐蚀前后的形貌变化。结果表明,在50℃的废水中,L-抗坏血酸的较适宜量0.100g/L;缓蚀剂成膜较适宜时间24h,其缓蚀效率达79%。当存在缓蚀剂膜时,Q235钢自腐蚀电流密度从5.46×10^(-5) A/cm^2降至3.81×10-8 A/cm^2;在0.400V过电势下,极化腐蚀电流密度从6.41×10^(-3) A/cm^2降至4.10×10^(-6) A/cm^2;极化阻抗从198.6Ω·cm^2增加至7546.3Ω·cm^2。SEM测试表明,在0.400V过电势下,无缓蚀剂膜的Q235钢腐蚀十分严重,有缓蚀剂膜的Q235钢几乎不腐蚀。

The ascorbic acid corrosion inhibitor on corrosion properties of Q235steel in the production wastewater of dibenzoyl methane at 50℃is studied by weight-loss method.The self-corrosion current density,polarization corrosion current density and polarization resistance of corrosion inhibitor film were determined by electrochemical method.The morphology of corrosion inhibitor Q235steel with and without corrosion inhibitor film is studied by SEM.The result reveals that in the wastewater of 50℃,the best dosage of ascorbic acid is 0.100g/L,and the optimal time of the corrosion inhibitor film formed is 24h,and corrosion inhibition efficiency equal to 79%.The self-corrosion current density of Q235steel is reduced from 5.46×10-5 A/cm2 to 3.81×10-8 A/cm2,when the corrosion inhibitor membrane is present.When the polarization voltage is 0.400V,the polarization corrosion current density decreases from 6.41×10-3 A/cm2 to 4.10×10-6 A/cm2,and the polarization impedance increases from 198.6Ω·cm2 to 7546.3Ω·cm2.The SEM test demonstrates that under the electric potential of 0.400V,the Q235steel without corrosion inhibitor film corrosion is very seriously corroded while the Q235steel with corrosion inhibitor film is hardly corroded.