基于恒电量的酸性缓蚀剂快速评价方法研究  

RAPID EVALUATING METHOD OF THECORROSION INHIBITORS IN ACIDIC SOLUTION BASED ON THE COULOSTATIC TECHNIQUE

作　　者：赵永韬[1,2] 郭兴蓬[1] 董泽华[1] 赵广宇[2] 

机构地区：[1]华中科技大学化学系,武汉430074 [2]七二五研究所青岛分部,海洋腐蚀与防护国防科技重点实验室,青岛266071

出　　处：《中国腐蚀与防护学报》2004年第2期116-120,共5页Journal of Chinese Society For Corrosion and Protection

基　　金：环境试验与观测"十.五"计划重点资助项目 (CZB1.1-1)

摘　　要：利用恒电量法快速测量了Q2 35钢在 0 5mol/L硫酸溶液及其硫脲缓蚀溶液中的腐蚀 ,建立了新的解析方法获得Tafel常数 ,探讨了恒电量激励条件下的等效电路 ,同时用电化学阻抗谱进行验证。结果表明 :恒电量法不仅能快速测量Rp 和Cd 值 ,而且可以及时获得添加缓蚀剂前后的B值 ,对于表面状态变化快的酸性缓蚀体系 ,能更加直接、准确地评价缓蚀剂 ;对恒电量测量 ,可以避免缓蚀剂吸脱附等慢过程的影响 ,用简单模型获得的Rt 值的大小 ,将大大地简化了酸性缓蚀剂的评价 .In this paper,the corrosion rate of mild steel in 0.5 mol/L sulphuric acid with and without thiourea were evaluated by the coulostatic technique,and a novel approach based on NLLS (Non-linear least square) fitting method was presented to get Tafel constant.Different kinds of equivalent circuit models such as R(CR(RL)) and R(RC) were discussed,and used to analyze the response to the coulostatic perturbation.In addition,electrochemical impedance spectroscopy (EIS) was used to confirm the results from the coulostatic method.The results show that the coulostatic technique can not only determine the values of R p,C d quickly,but also the Tafel coefficient timely both in the acidic solution with and without inhibitor,Therefore the coulostatic method is useful for a direct and rapid evaluation for corrosion inhibitors,especially for the changeful surface of metal in the acidic solution.Moreover,since the coulostatic measurement is a very rapid process,so that it is highly convenient to get R t by analyzing of the R(RC) circuit model,and that indicated that the evaluation process might be made much more simplified.

关 键 词：恒电量 硫酸溶液 硫脲 极化电阻 电荷传递电阻 

分 类 号：TG174.42[金属学及工艺—金属表面处理]