The application of quartz crystal microbalance (QCM ) in the study of atmospheric corrosion is reviewed.QCM is available to measure mass changes of a nanogram order and has widely been used for insitu investig ations of atmospheric corrosion.The effects of environmental factors, corrosive gas constituents and gasphase inhibitors on the atmospheric corrosion mechanis m of metal materials have been studied with QCM.In the recent years, the atmosph eric corrosivity probe based on QCM techniques has been developed.The character istics and developing trend of QCM for atmospheric corrosion investigation and m onitoring are analyzed and discussed.

Both the holidays crossing through the polyolefin t ape coating and the loss of adhesion of polyolefin tape result in poor protectiv e capabilities of coating.Galvanostatic step technique and electrochemical imped ance spectroscopy were used to investigate the electrochemical behavior of carbo n steel with coating of different failure.The difference of the voltage r esponse curves for the samples with different coating failures was observed and the ratio of the coating resistance to the gross resistance was proposed to dete rmine the coating condition.The degrading process of polyolefin tape immersed in to tap water was studied and it was found that the adhesion of coating degraded quickly for tape coating having holidays.The study demonstrated that in addition to EIS technique,galvanostatic step technique is another suitable method in stu dying coating-metal system.

Two methodssimulated occluded cell and simulated occluded solutionhave been developed to determine the protection potential aga inst pitting of A3 steel and 0Cr18Ni9 stainless steel.They are based on the theo ry that the pitting protection potential(EP) is actually the transition po tential of the direction of current between the occluded cell and the external s urface(ET).The ET of 304 SS in 0.5　mol·L-1 NaCl solution is in the range of 220 mV to 440 mV(SCE), the ET of A3 steel in 0.01 mol ·L-1 NaCl solution(pH=12) is in the range of 390～670 mV, the lowest of which can be considered as cathode protection potential(EP).The E P of 304 SS determined with “cyclic” potentiodynamic polarization method is included in the ET with above methods.As for electrochemical protection ag ainst pitting, if the potential of the external surface is controlled below the EP,the activepassive transition will occur inside the occluded cell, so the pitting will be stifled.

Artificial neural network(ANN) method for the data processing of high temperature sulfur corrosion is proposed after analyzing the g eneral method for high temperature sulfur corrosion. A metabolism model for pred icting the corrosion life by ANN is presented, which does not need all kinds of materials and environment parameters,and only needs to know a little data about environment parameters(including temperature,sulphur content and materials) and corr ositivity in-service.The feasibility of this model was verified by the data from McConomy and Coaper Gorman curves.It is proved that ANN technology is applicabl e to the evaluation of the complicated system of high temperature sulphur corros ion, and also gives a base to develop the expert system and residual life evalua tion system for high temperature sulphur corrosion.

A new OCC simulate cell has been designed to simul ated the autocatalytic process by the occluded corrosion cavity(OCC) on low allo y steel in 3.5% NaCl solution.The effects of geometrical factors of OCC simula ted cell have also been discussed.There are two important parameters in OCC whic h play an important role in localized corrosion process for low alloy steel, the height and diameter of occluded corrosion cavity.The corrosion rate increases with thes e two parameters.The suitable size of OCC is 3,3 for height and diameter of OCC which can simulate the corrosion tendency of five low alloy steels used as speci men in this experiment.The pitting corrosion rates of low alloy steels have been rank with the cell.The results are in agreement with the corrosion data got by long time immersion test in the sea.

A sphereplane contact device has been used to stu d y the fretting corrosionwear transferability of 316L stainless steel in saline solution. The evolution of fretting damage rates such as the total weight loss r ate (KTt), mechanical damage rate (Kmt), corrosion rate (K ct) and the damage induced by the synergistic effect between mechanical and chemical actions as a function of fretting cycle has been investigated. In t he same time, the variation of the components of mechanical action, corrosion ac tion and the synergistic effect in the total weight loss rate have also been stu died. The variations of KTt,Kmt,Kct were equal to each other. In spite of the difference between the variation of Kct an d the variations of KTt,Kmt,Kct,the fretting of 31 6L stainless steel was characteristic of three stages. And each of these three s tages was of the different mechanism. In the beginning of fretting the damage oc curred in local areas, and the material suffered ploughing damage because of the hard debris formed by fabrication of passive film. In the second period, seriou s crevice corrosion occurred nearby the fretted region, which has taken a great important role in the fretting process. And in the final period, the damage mech anism could be defined as corrosive flaking process. The results showed there wa s a relationship between the of damage rates and mechanisms. The synergistic eff ect took an important role in fretting, and in stable stage, more than 60 percent of fretting damage was due to the conjoint action of mechanical and chemical effects. The result finds the inter relationship between the transition s of fretting damage rates and the synergistic effect and the variation of damag e mechanisms in different fretting periods.

The oxidation behavior of Ni-20Cr alloy and its spu ttered microcrystalline coating have been studied in the presence of water vapor at 1000℃.The results indicate that the higher the water vapor content,the le ss the mass gain of the alloy.The composition of scale depends on the content o f water vapor.However,the water vapor content has only effect on the mass gain of the microcrystalline coating.The oxide scales were examined and analyzed by optical microscope(OM),X-ray diffraction(XRD) and scanning electron microscope (SEM) with EDX.The mechanism of the effect of water vapor on the alloy and its sputtered microcrystalline coatings was proposed.

TiO2 modified film is one of wonderful anticorros ion materials.TiO2 modified film on carbon steel was prepared by a new method electroless plating and solgel composite process.There were many preparation fa ctors influencing the corrosion resistance property of modified film,among them, the thickness of NiP transient layer (measured by plating time),number of dipc oating during the solgel process,heat treatment time and the molar ratio of c omplexing agent and Ti(OC4H9)4 were the most important ones.An artificial neural network was applied to design the preparation condition of TiO2 modifie d f ilm considering the interaction of the main factors.The condition of forming TiO 2 modified film on carbon steel was that NiP plating was 50minutes,No.of dip coating was 4,heat treatment time was 2 hours,and the molar ratio of complexing agent and Ti(OC4H9)4 kept 1.5∶1.Corrosion behavior of TiO2 film on carb on steel was investigated by polarization resistance measurement.The result show s that electroless plating and solgel TiO2 modified film on carbon steel has a good anticorrosion property in 0.5 mol/L H2SO4 solution.

Based on the theory of hydrogen enhanced local pla sticity of the hydrogen induced cracking,the paper presents a fractal model of h ydr ogen induced cracking,and sets up a relation among the effective surface energy Γ(H),fractal dimension D and stress intensity factor of hydrogen induc ed cracking KIH under hydrogen environment.The relationship of D a nd KISCC is obtained.The model is verified by experiment,and it showed that the method is reliable.

Four imidazoline inhibitors have been synthesized and determined by IR and UV spectral analyses. The inhibition efficiency was measured using weight l oss and electrochemical methods. It is found that percentage inhibition corrosio n is increased as in following order: compound I<Ⅱ<Ⅲ<Ⅵ. The relationship bet ween structure of the compounds and corrosion inhibition efficiency is explored from experiment. Through measured results and theoretical analyses, it is indica ted that imidazoline with P-π conjugated system and electron donor group, parti cularly, the substituent aromatic group, introduced to imidazoline ring can impr ove the inhibition efficiency of imidazoline derivatives.

A suit of electrochemical cell which was used to in vestigate the corrosion behavior of metals under different thin layer electrolyt e was designed.The Luggin probe of the cell was inserted backward of the working electrode.The results showed the layer thickness mainly affected the cathodic p rocess of Cu in the electrolyte (0.5 mol/L HCl+0.25 mol/L Na2SO4),the anodic dissolution changed from Tafel zone to limiting current zone.Moreover the corro sion potential increased with decreasing of the layer.