H2SO4中丙炔醇复配缓蚀剂对碳钢的缓蚀作用

目的探究不同温度下丙炔醇、KI及其复配对Q235碳钢和N80钢片在10%(质量分数)硫酸中的缓蚀性能。方法采用静态失重法和电化学方法,60℃下测定酸液中的单剂对Q235碳钢的缓蚀性,然后对二者进行复配研究。优化配比后升高实验温度,探究高温下不同配比在酸液中对N80钢片的缓蚀性能。根据吸附等温模型和腐蚀动力学对缓蚀机理进行初步探讨。结果失重法表明,60℃时单独使用丙炔醇、KI,当质量浓度分别为120、1000 mg/L时,对Q235碳钢的缓蚀率均达到90%,两者的使用浓度较高。复配后得到两个优选配比,配比A为丙炔醇18 mg/L+KI 250 mg/L,配比B为丙炔醇15 mg/L+KI 300 mg/L,配比A、B的缓蚀率均高达98%。配比A、B的缓蚀率均随温度升高而降低,配比A在80℃酸液中对N80的缓蚀率为93%,配比B在100℃酸液中的缓蚀率为73%。结论复配后缓蚀剂的使用量均降低,且在一定高温下具有良好的缓蚀性能,丙炔醇和KI有较好的协同作用。电化学的实验结果与失重法相一致,丙炔醇和复配剂为混合型缓蚀剂。缓蚀剂在金属表面的吸附为化学吸附,符合Langmuir吸附等温模型。

Inhibition Performances of Compounds of Propargyl Alcohol Inhibitior for Carbon Steel in H2SO4 Solution

ABSTRACT:Objective To study the inhibition ability of propargyl alcohol, potassium iodide and compound in 10% H2SO4 for Q235 carbon steel and N80 sheet steel at different temperature.Methods In this paper, the inhibition performance of the sin-gle dosage was measured by static weight-loss method and electrochemical method for Q235 carbon steel at 60℃, and then the compound was studied. The experimental temperature was increased after optimized to research the corrosion inhibition for N80 steel in acid solution with different proportions. The inhibitory mechanism was investigated by isothermal adsorption model and corrosion kinetics.Results The results reveal that if propargyl alcohol and potassium iodide were used alone to inhibit the corro-sion reaction in H2SO4 solution, the inhibition rate for Q235 carbon steel reached 90% at 60℃ whenthe concentrations were 120 mg/L and 1000 mg/L. There were two preferred ratios. The concentration A was propargyl alcohol 18 mg/L and KI 250 mg/L and that of B was propargyl alcohol 15 mg/L and KI 300 mg/L. The inhibition efficiency of them reached 98% at 60℃, that of A reached 93% at 80℃ for N80 and that of B reached 73% in H2SO4 environment at 100℃. The inhibition efficiencies decreased with increase in the temperature of the inhibitors.Conclusion The compounds sharply decrease after the concentra-tions of propargyl alcohol and potassium iodide and have good inhibition performance at high temperature. The synergistic ef-fect between them is obviously good. Results obtained from weight loss and electrochemistry methods are in good agreement. The results show that propargyl alcohol and compounds are mixed type corrosion inhibitors. The adsorption of these inhibitors on mild steel surface is chemical adsorption and obeys Langmiur isotherm.