水葫芦叶提取物对冷轧钢在H_2SO_4溶液中的缓蚀作用

Inhibition effects of Eichhornia Crassipes leaves extracts on cold rolled steel in H_2SO_4 solution

采用失重法研究了水葫芦(Eichhornia Crassipes)叶提取物(ECLE)对冷轧钢在0.1~0.5 mol/L H_2SO_4溶液中的缓蚀性能。结果表明:ECLE对冷轧钢在0.1 mol/L H2SO4溶液中具有良好的缓蚀作用,缓蚀率随缓蚀剂浓度的增加而增大。各温度下的缓蚀率大致排序为:40℃>30℃>50℃>25℃。ECLE在钢表面的吸附符合Langmuir吸附等温式,其吸附过程为含有物理吸附和化学吸附的混合吸附过程。冷轧钢在添加ECLE前、后的H2SO4溶液中的腐蚀速率随酸浓度的变化均符合Mathur经验公式;添加ECLE后腐蚀速率常数降低,但腐蚀反应动力学参数升高。

The inhibition effect of Eichhornia Crassipes leaves extract（ ECLE） on the corrosion of cold rolled steel in 0. 1-0. 5 mol/L H2 SO4 solution was studied by weight loss method. The results show that ECLE is a good inhibitor for cold rolled steel in H2 SO4 solution,and inhibition efficiency increases with the concentration of inhibitor. At different temperatures,the inhibition efficiency follows the order： 40 ℃ 30 ℃ 50 ℃ 25 ℃. The adsorption of ECLE on steel surface obeys Langmuir adsorption isotherm,and is a mixed adsorption process that involves both physical and chemical adsorption. The changing rule of corrosion rate of cold rolled steel with acid concentration followsMathur empirical equation. The corrosion rate constant decreases to more extent,while corrosion reaction kinetic parameter sharply increases.