Chronoamperometry(CA) was used to study the melt interface reaction in H₂S/CO₂ coexistence environment. The mathematic model for interface reaction of the process has been carried out. The action of adsorption, desorption and hydrogen absorption for interface reaction were analyzed using this model. The results demonstrated that when η=50 mV, the process of hydrogen adsorption is dominant and control whole interface reaction; when η>50 mV,the desorption process of pre-adsorption substance control whole interface reaction. CO₂ increases contribution of absorption-feature hydrogen to the i_total，so promotes hydrogen absorption in all experimental η condition.

Effects of Sn addition on corrosion rate of Mg-6Al-1.2Y-0.9Nd magnesium alloy in 3.5% NaCl solution were studied by the static mass-loss tests. The microstructures of the alloys were observed by optical microscope and the morphologies of corrosion surface were analyzed with scanning electron microscopy. The results indicated that with the addtion of 1% Sn, the crystal grain size of the Mg-6Al-1.2Y-0.9Nd magnesium alloy was obviously refined, the microstructure was more homogeneous. But when the addition of Sn is more than 1%, the precipitates increase and they cause the trend of coarsening and segregation. Furthermore, in NaCl solution the corrosion rate of Mg-6Al-1.2Y-0.9Nd magnesium alloy decreases firstly and then increases with the increase of Sn content. With the addtion of 1% Sn, the corrosion rate of the alloy was the lowest, and the corrosion resistance was improved remarkably.

The potentiodynamic scanning curves and the electrochemical coupling behaviors of constituent phases at the grain boundary of Al-Mg-Si alloy were investigated. The corrosion mechanism of Al-Mg-Si alloys different ratio of Mg to Si was analyzed. The results show that the Si particle is cathodic to the Al-base and causes the anodic dissolution of Al-base at its adjacent periphery. At the beginning, the precipitate of Mg₂Si is anodic to the Al-base and corrosion occurs on its surface. However, during its corrosion process, its potential moves to a positive direction with immersion time increasing, due to the preferential dissolution of Mg and the enrichment of Si, which makes Mg2Si become cathodic to Al- base and leads to the anodic dissolution of the Al-base at its adjacent periphery at a later stage. At the grain boundary of Al-Mg-Si alloys with a ratio of Mg to Si higher than 1.73, the Mg-and-Si contained precipitates are distributed discontinuously, resulting in that they are not sensitive to intergranular corrosion. There exist Mg-and-Si-contained precipitates and Si particles at the grain boundary of Al-Mg-Si alloys with a ratio of Mg to Si less than 1.73, corrosion occurs firstly on the surface of Mg₂Si. Meanwhile, the Si particle leads to the great anodic dissolution of the precipitate-free-zone(PFZ) at its adjacent periphery. The Si particle also accelerates the preferential dissolution of Mg in Mg₂Si precipitate, expediting the polarity transformation between Mg₂Si and the PFZ. As a result, the corrosion development along the PFZ at the adjacent of Mg₂Si particle is enhanced.

Atmospheric corrosion was widely occurred when metallic materials were used in natural environment. This paper presents a cellular automata model which simulates the early stage of metal corrosion in moist atmospheric environment. First, the basic principles of cellular automata are introduced, and the application of cellular automata in corrosion field is briefly summarized. Then according to the mechanism of metal corrosion in moist atmospheric environment, the cellular automata model which will simulate the electrochemical reactions and diffusion steps of metal corrosion is proposed. With a series of simulation, the optimization factors which were used to simulate the evolvement of corrosion pit appearance are established. At the same time, the concentrations of different cells in electrolyte are simulated, and the trend of the concentration curve is analyzed contrast to the lab experiment.

Low cycle fatigue tests were performed for a type 316Ti stainless steel in high temperature and pressure water. Fatigue crack propagation, fracture behaviors and relative mechanism of environmentally assisted cracking were investigated. It was found that fatigue cracks were transgranular fracture. Cracks show tortuous behavior, and cracks were coalescence, branch deflection each other. At the high strain rate, the cracks were shorter and the number was larger, but at the low strain rate, the cracks were taller and the number was fewer. Meanwhile, striation spacing was longer at the low strain rate than that at high strain rate. Crack tip produced strongly plastic deformation and a lot of slip bands, and it was found some secondary cracks before and both sides of the crack tip. It is believed that synergism between the mechanical factors and electrochemical reactions played a key role in the process of fatigue crack propagation in high temperature water. Slip-dissolution model was proposed for explaining the related fatigue crack propagation mechanisms.

Electrochemical impedance spectroscope (EIS) of B95 aluminum alloy in 0.01 mol/L CeCl₃ solution was investigated to study the film formation. The changes of EIS in the film formation help to study the influence of pH on the film formation of B95 aluminum alloys. Followed is an analysis on the tested EIS based on equivalent circuit. The result shows that Ce conversion coating can not be formed when B95 aluminum alloy is in 0.01 mol/L CeCl₃ solution at the pH=3.0 Increaing the [H⁺] of solution will do good to the dissolution and activation of aluminum alloy, and accelerate the first stage, but to disadvantage the formation of Ce(III) hydrate and oxide. As the pH increases, the rate of aluminum alloy dissolution and activation will decrease. Such decrease will affect  the film formation stage. But it is good for the aggradation of the Ce(III) hydrate and oxide, and  the thickness and the compactness of the film. In neutral or subacidity solution, increasing the pH of solution will do good to the final formation of Ce（III） conversion coating.

Electric field treatment was performed on one of nickel-base superalloy GH3044 and the effects of electric field treatment on the microstructure and corrosion behavior of the alloy were investigated. The results show that the intergranular corrosion resistance of the alloy is improved by the electric field treatment and the intergranular corrosion rate decreases with the increasing treatment time. The intergranular corrosion rate is 2.06 mm/a when the alloy is electric field treated under the condition of 800 ℃ and 6.4 kV/cm for 10 h, and the decreasing extent reaches 37.33 % compared with the alloy untreated. The formation of the annealing twins during the electric field treatment cause the redistribution of atoms of the crossings between the original high angle grain boundaries and the annealing twins. With the increase of electric field treated time, a large amount of original high angle grain boundaries are replaced and the continuous distribution of depletion network of the alloying element is separated, those lead to the retardation of the corrosion ditches to go forward. The intergranular corrosion resistance of the superalloy is improved due to the improving of intergranular corrosion behavior of the grain boundaries. Moreover, the promotion effect of electric field treatment on atom diffusion rate decrease the exhaustion tendency of Cr and Mo elements on both sides of normal high angle grain boundary. Those can be considered as the reasons of improving the corrosion resistance after electric field treatment.

Catalyst attrition resistance is extremely important in the operation of fluid catalytic cracking (FCC) units because of potential problems with loss of catalyst and contamination of the subsequent products. Attrition behavior of several FCC catalysts and catalyst additives in oil refineries was investigated through lab-scale jet-cup test. The influences of ambient hydrodynamic parameters and material characteristic properties on particle attrition mechanism were mainly explored and clarified. The experimental results indicate that the particle size distribution has great influence on the attrition behavior of the catalysts tested, and a mixed attrition mechanism consisting of abrasion and fragmentation is identified for all the catalysts in terms of attrition loss rate evaluation, after-attrition morphology characterization and particle size distribution analysis. It is shown that the attrition of particles was found to evolute following Gwyn’s kinetic model and the difference of attrition mechanism of various particles can be categorized with parameters of the Gwyn equation.

Effect of size on corrosion behavior of 304 stainless steel micro-electrodes was investigated using electrochemical methods (including potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), and electrochemical noise (ECN)). The results of potentiodynamic polarization and EIS indicated there is a non-linear relationship between the limiting diffusion current density and the area of electrode. The limiting diffusion current density, the corrosion current density and the double-layer capacitance increased with decreasing the electrode size. On the other hand, the corrosion potential negatively shifted and the solution resistance decreased with the decrease of electrode size. The results of ECN demonstrated that there is a critical size for metastable pitting, the frequency of metastable pitting reduced obviously with the decrease of electrode size.

The ever-increasing demand for petroleum and natural gas, requires high strength pipeline steels for transportation. In the transporting process, the hydrogen induced cracking (HIC) on the pipeline steels in a H₂S environment is the main reason to cause corrosion problems and technical problems. For this reason, it is necessary to study the HIC phenomenon in high strength pipeline steels. The HIC sensitivity，of the experimental X120 high strength pipeline steel was tested, the nonmetallic inclusions in the X120 pipeline steel was studied by using a multifunctional microscope, and the cracks formed by HIC were analyzed by SEM and EDS. The results show that the cracks usually initiate and extend at the boundaries between nonmetallic inclusions and the base metal, and connect with each other; long cracks are more easily formed near the B type inclusions than near the D type inclusions; larger contents of the S and Al in the X120 pipeline steel, higher grade of the inclusions, and larger amount of the nonmetallic inclusions, lead to higher HIC sensitivity.

Arc ion plating (AIP) was used to produce NiCrAlY and NiCrAlYRe overlay coatings. After heat treatment in vacuum, both of the coatings consisted of γ‘-Ni₃Al, γ-Ni, β-NiAl and α-Cr. Re in the NiCrAlYRe coating existed in α-Cr and promoted the precipitation and thermal stability of α-Cr. The existence of α-Cr in the interface of coating and substrate lowered coefficient of thermal expansion and thus reduced thermal stress in the surface scale, improving adherence of the scale. The addition of Re obviously increased hot corrosion resistance of NiCrAlY in 90%Na₂SO₄+10 mass%K₂SO₄.

In aqueous electrolytes, electrodeposition on Mg alloys is still a challenge because Mg has high chemical reactivity. The process becomes more complicated in aqueous electrolytes owing to the hydrogen evolution. Ionic liquids as non-aqueous electrolytes in electrodeposition have received much attention from researchers. In present study, choline chloride-urea ionic liquid, which is sustainable, biodegradable and stable in air and water, was used as the solvent and the electrodeposition of Zn on AZ91D magnesium alloy was investigated. The pretreatment mechanism of the AZ91D substrate and the effect of current mode on the Zn coatings were studied by scanning electron microscope (SEM/EDX). The corrosion resistance of the deposited Zn coatings were studied by electrochemical testing. The results show, Zn coatings could be electrodeposited on pretreated AZ91D substrate from choline chloride-urea ionic liquid. Application of pulse deposition was superior to galvanostatic deposition in producing dense, uniform and cohesive Zn coating. By pulse deposition Zn coatings, the OCP of AZ91D substrate moves in positive direction from -1610 mV to -1072 mV and the corrosion current density I_corr decreases from 14.9 μA/cm² to 6.9 μA/cm²，comparable to those of pure Zn (OCP=-1078 mV， I_corr=6.6 μA/cm²).

Corrosion rate of P110 steel was investigated by the mass loss method in sulfur deposition environment with different temperature and different acid of the experimental system that simulated the downhole environment of PUGUANG gas field. Meanwhile, the corrosion product scales were analyzed by SEM, EDS and XRD technology, and the method of electrochemistry was used to test the effect of sulfur to corrosion rate. The results showed that the reason why the corrosion rate greatly increased is the disproportionation reaction resulting in the increasing of H⁺ and HS^-/S^2- which were more aggressive than Cl^-. The corrosion rate firstly increased and then decreased with the temperature and time increasing, and the content of sulfur of corrosion products increased from the matrix to the outer layer. The result of film potential measure indicated that the increasing of corrosion rate was closely related to the inhancing of the anion selective of the corrosion product scales.

Steel is the most important engineering material while galvanizing is the most effective method for corrosion protection of steel. This article reports the results of a study on the efficiency of corrosion protection by zinc coating in various natural environments based the corrosion rate data collected from various parts in the world. The potential and development direction for more corrosion resistant zinc based coatings are then discussed. More corrosion resistant zinc coatings could extend the application of galvanized steel beyond atmospheric environments much more into other environments such as soil, water, concrete or chemical environments. Comments are also made regarding the relevance of corrosion tests in relation to new coating development.  This article was written in behalf of the International Zinc Association.

After summarizing the major achievements in the field of marine biofouling and marine corrosion, this paper attempts to review the influence of biofouling on the corrosion behaviour. The corrosion effect of microfouling and macrofouling is respectively discussed, and the mechanism is also analyzed in this paper. Last, further development in this field is proposed.