Effect of oxide film on the corrosion behaviors of the steel of B510L hot rolled strip was investigated by potentiodynamic polarization curves and electrochemical impedance spectroscope(EIS). The results indicated that the oxide film had no effect on the mechanism of the anodic reaction, cathodic reaction and the corrosion of carbon steel. The poor protection of the oxide film with defects led to the corrosion of the metal. Porosity of the oxide film could be calculated from the analysis of potentiodynamic polarization curves and electrochemical impedance spectroscope(EIS).

According to material corrosion data, a grey neural network forecasting model is proposed. The model is integrating GM(1,1)model and RBF artificial neural network model and it is also simulated using the material corrosion data .The result showed that the grey neural network integrated forecasting model could satisfactorily predict the corrosion rate of carbon steel and low alloy steel in different sea water environment for a long time, and it also give a better prediction of the corrosion than those given by GM(1,1) model

Abstract: The effects of rare earth Ce addition on the microstructures and corrosion resistance of AZ91 alloys were studied by XRD, SEM, EDS, potentiodynamic polarization and immersion test. The mechanics of the corrosion resistance increased with Ce was analyzed from thermodynamics point. The results showed that: the microstructure of the alloys were refined by adding Ce; β-Mg17Al12 phase was broken, dispersed and the elements distributed uniformly; The Al4Ce phase and Mg-Al-Mn-Ce intermetallics were observed by adding Ce; Anodic polarization of the alloys increased and Al-Ce-O oxidation film were obtained because of adding Ce to the AZ91 alloy; When the amount of Ce was 0.5wt% the corrosion resistant of the alloy is the best.

The measurement of electrochemical impedance was accomplished based on data correlation filtering technology under LabVIEW8.0 software. By contrast with normal electrochemical measuring instrument,the system achieves a good effect in the range from 10mHz to 10kHz,and can be used in common electrochemical impedance measurement.

The corrosion electrochemical behavior of cast uranium has been studied in 0.5mol•L-1 H2SO4, 1mol•L-1 NaOH and 1mol•L-1 Na2SO4 solutions respectively using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results obtained by potentiodynamic polarization curves indicated that there appear “fake-passivity” phenomena in H2SO4 and Na2SO4 solutions, while in NaOH solution it exhibited a additional “passivity” region besides the former phenomena. The EIS results all exhibit obvious capacitance-resistance arc characteristic. The software named ZsimpWin was used to fit the data form EIS to obtain corresponding equivalent circuit which consistent well with the measured data. The physical model of corrosion for uranium in three different solutions were proposed to interpret their equivalent circuits. The chi-square values between simulated data and measured data are within 10-3 order of magnitude.

The corrosion resistance of the two types of microarc oxidation (MAO) coatings was evaluated by virtue of total immersion test and salt spray. Then the mechanism of the coating corrosion failure in 5wt.%NaCl aqueous solution was studied through the impedance and open-circuit potential (OCP) measurements. The results showed that both phosphate coating (P-film) and silicate coating (Si-film) could enhance the corrosion resistance of AZ91D alloy significantly and that the later was more effective. Based on the variations of OCP and corrosion morphology of P-film and Si-film immersed in 5wt.%NaCl aqueous solution with different time, the analytic results of electrochemical impedance spectroscopy (EIS) data for Si-film showed the corrosion failure process had experienced the following four steps: the rapid initial penetration of the solution into the porous outer layer; the filling of corrosion products in certain pores; the gradual corrosion of the barrier layer located in the bottom of pores; the stable corrosion process with the failure of barrier layer.

The erosion-corrosion behavior and mechanism of high velocity arc sprayed FeCrAl coating and 3Cr13 coating in acid slurry were studied by liquid-solid two-phase flow erosion-corrosion tester. The morphology of the surfaces after erosion-corrosion was observed using a scanning electron microscope (SEM). It was found that the damage of coatings reinforced as erosion speed increased. The erosion-corrosion mass loss rate of FeCrAl coating was much lower than that of 3Cr13 coating. The FeCrAl coating had better corrosion resistance than the 3Cr13 coating. In the weight loss process of FeCrAl coating erosion was dominating, and corrosion played the same role for 3Cr13 coating. It was observed that the maximum value of erosion-corrosion mass loss rate of both coatings appeared when the erosion angle was at 30 degree. The reason was that the value of the erosion loss rate reached maximum at this angle. Cutting was dominating in erosion-wear mechanism at low angles, while both cutting and impact took effect at high angles.

The inhibitive effect of new synthetical triazole derivative was evaluated in 1MHCl using weight-loss、electrochemical methode. The adsorption of triazole derivative on Q235-A steel surface was studied by weight-loss. The results showed that the triazole derivative is a mixed-type inhibitor, the highest inhibition efficiency is up to 95%. It was seen that the adsorption of triazole derivative on Q235 steel can be fitted to Langmuir isotherm equation, and the adsorption is endothermic reaction.

Abstract： The inhibition of DL-Cysteine assembled membrane for copper corrosion in 0.5M HCl solution was investigated by electrochemical measurement. The result shows that the mono-layer self-assembled DL-Cysteine has protection effect and it retards the cathodic process of the corrosion electrochemical reaction. The bilayer membrane was assembled on copper electrode by electrostatic interaction between l-dodecanoic acid and DL-Cysteine. This kind of bilayer membrane can strengthen the inhibition for cathodic process of copper electrode and improve the protection effect for copper.

By means of optical emission spectrometer, universal material testing machine, optical microscope, scanning electronic microscope and finite element calculation were used to analyze the multi-cracking reason of 7020 aluminum alloy train coupler girder, and study results indicated that stress corrosion cracking (SCC) caused by wet and sweltering hot weather .According to finite element calculation results it could be known there was no stress at the “Z” direction, and welding residual tension stress is the main cracking reason. Modeling test results of DCB samples showed that the cracking mode of train coupler girder and DCB sample is same. Cracking mechanism of 7020 aluminum alloy was researched and discussed.

The effect of chemical composites and microstructure on CO2 corrosion of steels was reviewed. The relations of morphology, microstructure and protection property of CO2 corrosion scale to chemical composites and microstructure were discussed. The present research situation of CO2 corrosion electrochemistry was also analyzed. Then the difficulty and main direction for further research were pointed out.

A brief review of the SCC mechanism of 7xxx series aluminum alloys and the main factors which influence the SCC behavior of 7xxx series aluminum alloys are discussed at emphasis, meanwhile，Several new methods which can applied to SCC tests are introduced. Finally, the importance to further research SCC theory of Al alloy for increasing their SCC resistance is emphasized.