复配咪唑啉类酸洗缓蚀剂的缓蚀性能研究

Inhibition Performance of Composite Imidazoline Pickling Inhibitor

为了减缓酸洗过程中金属制品的严重腐蚀,酸洗缓蚀剂被广泛使用,开发使用方便、低毒、低剂量、环保的酸洗缓蚀剂很有意义。利用失重法、动电位扫描法和电化学交流阻抗法对复配咪唑啉类缓蚀剂LAN的耐蚀性能进行了研究。结果表明:在50℃的5%(质量分数)盐酸中加入0·3%(质量分数)的LAN能有效地提高碳钢的耐蚀性能;LAN的缓蚀作用机理系几何覆盖效应,它在金属表面吸附成膜后,使阴极和阳极过程都受到了阻滞。同时,根据EIS谱提出了相应的特征等效电路。

Though various inhibitors have been widely used to reduce metal corrosion in pickling process, it is still imperative to develop novel inhibitors of easy operation,low toxicity,high efficiency,and good environmental acceptability. Thus the inhibition behavior of composite imidazoline inhibitor LAN was studied by means of weight-loss,potentiodynamic polarization curve,and electrochemical impedance spectroscopy (EIS).The results indicated that the inhibitor LAN was able to effectively prevent carbon steel from corrosion in 5% HCl solution at 50 ℃.This was attributed to the formation of a LAN adsorbed film on the surface of the carbon steel,which contributed to simultaneously retard the anodic and cathodic corrosion process.Moreover,an equivalent circuit was proposed as a physical model to illustrate the absorption mechanism of the LAN adsorbed film, based on the EIS result.