The corrosion behaviors of typical high-strength aluminum alloy LC4 was studied by accelerated corrosion tests of cyclic wet-dry intermittent immersion designed to simulated industrially polluted atmospheric environment, and corrosion mechanism was also discussed. The main experimental techniques include mass loss, morphological check of samples and analysis of corrosion products in different test time. The result shows that LC4, with or without cladding, has linear relationship of mass loss and test time in two chemical media, 0.02 mol/L NaHSO3 and 0.02 mol/L NaHSO3+0.006 mol/L NaCl respectively. Angle of setting samples was another important factor that can cause corrosion of aluminum alloys. Angle of setting exerts its effect by varying the wetness time of the surface of samples, longer wetness time with less angle of setting and vice versa. A layer of cladding on high-strength aluminum alloys can raise resistance of atmospheric corrosion evidently.

Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were used to study the influences of sealing methods on the corrosion behavior of anodic oxide film on LD7 aluminum alloy in NaCl solution. The anodic oxide films were sealed by the methods of boiling water, nickel fluoride, potassium dichromate and nickel acetate, respectively. The surface morphology was examined by scanning electron microscopy (SEM). The results show that nickel acetate sealed film provides relatively higher corrosion resistance both in acidic and in basic solutions, while boiling water and nickel fluoride sealed films is better in neutral solution. Potassium dichromate sealing method, which is very popular in the industry, could not provide good sealing quality for anodic oxide film on LD7 aluminum alloy in acidic, neutral and basic NaCl solutions.

By using optical microscopy, X-ray diffraction(XRD) and electrochemical impedance spectroscopy(EIS) technique, the structure, composition characteristics and the electrochemical properties of micro-arc oxidation(MAO) coatings prepared at different current density on AZ91D magnesium alloy were studied. It was found that with increasing the current density, the growth rate of the coating and its crystallization became higher, while the roughness and porosity of the coatings increased, and the film resistance Rf decreased. The properties of the coating were not cetermined by the total thickness, but the structure of the coating.

The open-circuit potential、work potential、self-corrosion rate and anode efficiency of Al-0.05Ga-1Mg、 Al-0.1Ga-1Mg (with and without thermal treatment ) have been studied in 25℃ 、4mol/L KOH solution, and the change of main segregation of anodes have been researched by EPMA and energy spectrum analysis. The results show that the potential of aluminum alloys move to negative with the increasing of Ga from 0.05% to 0.1%; Fe、Si mainly exist in grain boundary;the content of element Mg increases after thermal treatment ,that is harmful to the property of aluminum alloys; thermal treatment increases the cathode phase, the anode dfficiency decreases woth the cathode increasing and dropping.

The corrosion-resistance properties of new grid alloy and traditional alloy were studied using anodic polarization curve and A.C impendance. The anodic films of comparative alloys formed in sulfuric solution at anodic 0.9V potential corrosion for 6h were investigated by means of XPS and XRD methods. The result showed that new grid alloy has batter corrosion-resistance behavior than that of traditional alloy, the growth of Pb(Ⅱ) dioxide in new alloy surface layer was inhabited. By means of A.C impendance method, the resistor of the corrosion layers were decreased, it was found that the new alloy can encourage the development of PbO2 in the scale, and enhance the conductivity of the anocdic scale, then, the deep recycling properties of the battery was promoted greatly. The new alloy can serve as the candidate for the grid material in maintenance-free lead/acid battery.

High temperature oxidation and hot corrosion behavior of sputtered NiCrAlY and enamel/NiCrAlY composite coating have been studied. The results indicated that at 900℃ an Al2O3 scale formed on the sputtered NiCrAlY coating, which offered good protectiveness. The coating with enamel overlayers greatly improved the oxidation behavior of NiCrAlY coating. No obvious oxidation scale was formed at the boundary of coating and enamel. At 850℃, the coating with enamel overlayers exhibited more excellent hot corrosion resistance in the molten salt than sputtered NiCrAlY coating. Neither internal sulfidation nor oxidation occurred on the samples with the enamel coating and the composition of the enamels changed little.

In ultrasonic field, nanocomposite coating was got by adding oil-soluble carbon black nanoparticles synthesized by surface graft modification into paint. SPM image and TEM picture showed that the particle size was about 24nm to 300nm and dispersed uniformly in coatings. Immersion corrosion testing, anodic polarization and electrochemical impedance spectroscopy (EIS) were employed to study the corrosion behavior of nanocomposite coating. The results indicated that the anti-corrosion performance of composite coating in NaCl solution was improved. The composite coating with 1mass% carbon black nanoparticles had the best corrosion resistance, and the corrosive mechanism was studied by EIS and TEM.

The pit corrosion resistances of nickel - chromium series low alloy structural hull steels were compared by simulating occluded corrosion cell test and interval laboratory immersion corrosion tests. The short - term immersion corrosion results showed that in early pit propagation stage, the rates of pitting propagation of nickel-chromium steels were slower than those of manganese steels.However,the results of the simulating occluded corrosion cell tests showed that the pitting resistance of nickel- chromium steels were lower than that of manganese steels when simulating long-term immersion corrosion test.However, pitting initiation stage of nickel- chromium steels with coating is much longer than that of manganese steels with coating. Therefore the resistance of nickel- chromium steels is bigger than that of maganese steels in practical use.

Based on the database of materials degradation property and corrosion, a fitness-for-service (FFS) software system for fire damage was implemented to evaluate equipment safety and calculate the residual lifetime. The system is established on three evaluation standards, which belong to the distinct safety grade with different test parameters. The software system can automatically give the results of applicability with the input data, such as thickness, deformation, temperature, pressure, hardness and so on. The testing showed that the software can be used to make run/repair/replace decisions. The application of FFS for fire damage will ensure that damaged pressurized equipment can continue to operate safely.

The accelerated corrosive environment spectrum and the accelerated corrosion test methods were studied for evaluation the local environment corrosion in the typical aircraft structures. The comparative tests for the heavy-duty coating SEBF/SLF and the ordinary coating on the active service aircraft structures were carried out. The results indicated that the anticorrosive properties of the heavy-duty coating SEBF/SLF are much better than the ordinary coating on the active service aircraft structures.

The effect of inhibiting H2-evolution for O-aminophenol on Al-alloy anode in 4mol/L KOH was studied by galvanostatic gathering volumes of hydrogen evolution and stable state polarization curves and electrochemical impedance spectrum . The mechanism of inhibing H2-evolution for O-aminophenol was studied also in this paper. The results show that the self-dissoution of Al-anode is very heavy, and the H2-evolution quantity manifested typical "positive difference effect". O-aminophenol incuding phenyl ,amidocyanogen and hydroxyl absorbs easily on the surface of mental, which decreases the absorption quantity of OH－ on the surface of Al-anode, and decreases the volumes of hydrogen evolution. The performance of Al-Ga-Sn-Mg does not get poorer and the "positive difference effect" of Al-anode does not change, which manifestes O-aminophenol is an appropriate inhibitor in this system.

Electrodeposited zinc and zinc-based alloys are widely used as the protective coatings of metals,and the nature of their atmospheric deterioration is their electrochemical corrsion under thin elecrolyte film.This paper reviews the influence mechnism of several important aggressive particles on the corrosion process of zinc and its alloys,and the main measuremerts usually used in the atmospheric corrosion study and their corresponding merits and limitation.Meanwhile,the prospetive points in future atmospheric corrosion study of zinc and its alloys are brought forward.