Study On The Anti-corrosion Performance And Mechanism Of The Environment-friendly Corrosion Inhibitor For Reinforcing Steel Bar

The corrosion of reinforcing steel bars is the primary and key element, whichleads to the destruction and malfunction of the structures of marine reinforcedconcrete. The corrosion inhibitor, with its profound advantages as being convenient,economical and effective, has been studied and researched with immense attentionand effort. However, currently there's still no in-depth and systematic research,focusing on the anti-corrosion performance and mechanism of environment-friendlycorrosion inhibitor for rebar.This thesis, directed by the Quantitative Structure Activity Relationship (QSAR),synthesizes and selects five organic environment-friendly inhibitor compounds,respectively, ascorbic acid (vitamin C), nicotinic acid (vitamin B3) and pyridoxine(vitamin B6) under the vitamin category, uniconazole and triadimefon under thetriazole category; also uses the electrochemical impedance spectroscopy (EIS) tostudy how the anti-corrosion performance of the two inter-phase inhibitors changes,with varied concentration, temperature and time.Through utilizing the cyclic voltammetry and the electrochemical Raman spectratechnology, a time resolved in-situ analysis has been conducted of the chemicalreaction of the five inhibitors on the surfaces of pure iron electrodes in alkalinesolution. Therefore a proposition has been raised that in the spontaneous passive film,there's formation of lattice FeIIand interstitial FeIIof two different energy levels,which reveals the reason why passive film gets deteriorated. The rotatingelectrochemical quartz crystal microbalance (abbreviated as rEQCM) has been utilized to study the vertical thermodynamic adsorption behavior of the five corrosioninhibitors on both surfaces of active and passive irons. With the help of SEM-ATRFTIR as well as the contrast-enhanced microscope, the inter-phase corrosioninhibitors' two landscapes of formed film, along with the natural law of corrosion anddeterioration of the passive film has been studied. Also the spinel crystal structurebased on interstitial-excess Fe3O4has been established, which reflects the mechanismof the interaction between the inter-phase corrosion inhibitor and the spontaneouspassive film on iron surfaces in alkaline solution.