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.

    時間：2016年8月10日10:30-11:00

    報告人：左禹

    個人簡介

左禹教授

    現任北京化工大學教授，博士生導師，現任中國腐蝕與防護學會監事長、國際腐蝕理事會（ICC）理事、教育部科技委委員暨材料學部委員、金屬腐蝕與防護國家重點實驗室學術委員會委員兼客座研究員等學術職務。

    主要研究方向為金屬局部腐蝕機理、電化學測試及表面保護技術；負責完成了國家自然科學基金、支撐計劃、國防基礎及配套等各類科研項目50余項，在國內外核心學術期刊上。發表論文330余篇，獲國家科技進步二等獎1項，部級科技進步獎5項。