Inhibition Behavior and Mechanism of Calcium Lignosulfonate on Steel in Simulated Concrete Pore Solution

  [abstract] Potentiodynamic polarization measurements, microscopy infrared imaging （M-IR） and X-ray photoelectron spectroscopy （XPS） were used to study the inhibition behavior of calcium lignosulfonate （CLS） on Q235 steel in 0.1 mol/L NaCl + Ca（OH）2 solution. CLS showed good inhibition for steel in the solution even after 7200 h immersion. In the solution of pH between 7 and 9.5, carbon steel was in active state. 0.001 mol/L CLS in the solution effectively inhibited both the cathodic and the anodic reactions. When the solution pH value increased to 9.5~10.5, passivation occurred and the main compositions of the passive film include Fe2O3, FeOOH, FeO and CaO/Ca（OH）2. CLS promoted the passive state and raised the pitting corrosion potential Eb. In the solution of pH 7~9.5, an inhibition film formed by the sulfonic acid group and the benzene ring in CLS molecular adsorbing on the surface. When the pH value increased to 10.5, a Ca-O-S cor-adsorption structure could form between ?SO3 group in CLS and the outer side layer of the passive film which is composed of CaO/Ca（OH）2. The strong adsorption characteristic between ?SO3 group in the adsorbed CLS on the surface and Ca2+ ions in solution may further improve the compactness of the adsorption film. The M-IR images showed that at the early stage of immersion the characteristic adsorption happened for CLS at the corroded areas on the surface, which would be helpful for preventing initiation and propagation of both general and pitting corrosion. The results show that CLS is a good inhibitor for steel bars in concrete structures for marine engineering.

  时间：2016年8月10日10:30-11:00

  报告人：左禹

  个人简介

左禹教授

  现任北京化工大学教授，博士生导师，现任中国腐蚀与防护学会监事长、国际腐蚀理事会（ICC）理事、教育部科技委委员暨材料学部委员、金属腐蚀与防护国家重点实验室学术委员会委员兼客座研究员等学术职务。

  主要研究方向为金属局部腐蚀机理、电化学测试及表面保护技术；负责完成了国家自然科学基金、支撑计划、国防基础及配套等各类科研项目50余项，在国内外核心学术期刊上。发表论文330余篇，获国家科技进步二等奖1项，部级科技进步奖5项。