Magnesium alloys are potential biodegradable materials for their outstanding biological performance. More attention has been paid on biodegradable magnesium alloys in recent years. However, the degradation of magnesium alloys is too fast in human body fluid or blood plasma. Ways to improve their corrosion resistance include modification of alloy compositions and proper surface treatment. This paper discusses the corrosion mechanism of magnesium alloys as biomaterials and the influencing factors. Also, progresses achieved in improvement of the corrosion resistance in recent years are reviewed. Finally the problems and trends for their application as biomaterials are proposed.

Progress at home and abroad of corrosion research for nanocrystallized metals is introduced in this paper. Different effects on corrosion performance of nanocrystallized metals are discussed. The influencing factors on corrosion behavior of nanocrystallized metals are analysed. The reasons for different corrosion performance of nanocrystallized metals are summarized.

The fouling organism accreted to marine installations is a major factor affecting their safety and service life. The tarnish of marine fouling organism to marine structures such as ships has become tremendous impediment to human activity in ocean. This article summarizes the adhesion mechanism and scathes of marine organism. Besides, the main antifouling methods at present, which classified as physical method, chemical method and biological method, are analyzed in term of antifouling mechanism, relative merits and so on. Finally, the future trends of antifouling methods research and development have been suggested.

During ordinary operation of a pressurized water reactor (PWR) of nuclear power plant (NPP), some deleterious ionic impurities such as Cl^－, SO⁴_2－, Ca²⁺, ^Mg2+, Al³⁺ etc. hidden in fouling and crevices for secondary side of steam generator (SG) would concentrate especially in flow-restricted regions. Concentrating situation of the deleterious impurities could be evaluated through secondary water chemistry measurement. In this paper, evaluation and analysis were made from three sets of practical hideout return (HOR) testing data for a NPP. The results indicated that pHT in crevice was in ordinary range from viewpoint of corrosion resistance according to HOR data. However, the concentration of Al³⁺ increased year by year and the reasons need to be further investigated. It is suggested that the time of hideout return tests during steady state should be extended so that the impurities could be completely returned.

A complex acrylate resin coating was synthesised on galvanized steel sheet. The micro-morphology of the coating was observed by SEM. FTIR spectra was used to characterize the molecular structure of the complex acrylate resin coating. The corrosion resistance of the coating was evaluated by neutral salt spray test and electrochemistry test. The self-rehealing performance of the coating was examined with immersion scratch test. The results show that the surface of the coating was uniform and compact. The coating could endure neutral salt spray test for 72 h. And therewith increase the corrosion resistance of galvanized steel sheet with higher impedance and polarization resistance in comparison to the bare galvanized steel sheet. The immersion scratch experiment confirmed that the coating exhibited self-rehealing performance to some extence. The crosslinking reactions may be taken place between ammonium zirconium carbonate(AZC) and hydroxyl and carboxyl of the acrylic resin during synthesis so that to form a high crosslinked density interpenetrating structure network so that the coating could become much effective as a barrier for corrosive substances. When the coating was damaged, there was reaction might take place between zinc with molybdate and phosphate on the surface of zinc to produce water-insoluble salts, which could absorb on the surface of zinc spontaneously to play an important role in coating rehealing.

Electrochemical measurement, slow strain rate test and SEM observation of fracture surfaces were used to study the corrosion behavior of 321 stainless steel in desalinated seawater. The result of cyclic voltammetry indicates that the pitting potential goes negative with the temperature rising, and thereby the pitting corrosion resistance decreases. Critical pitting temperature (CPT) of 321 stainless steel is 30.5 ℃ in desalinated seawater. SSRT results show that 321 stainless steel is relatively sensitive in desalinated seawater. At 35 ℃ and 50 ℃, 321 stainless steel shows ductile fracture, however the fractured surfaces exhibit ductile plus quasi-cleavage fracture at 70 ℃, and the sensitivity of SCC is inceraesed.

AZ91D magnesium alloy, was treated in solutions of phytic acid at different temperature. SEM, Tafel and EIS were adopted and spot test was carried out to investigate the influence of processing temperature on appearance and corrosion resistance of conversion coating. Results show that the phytic acid conversion coating have better corrosion resistance when magnesium alloy was treated in a temperature range between 20 ℃ and 35 ℃. The corrosion resistance would become poor of the coatings prepared at temperature beyong the above range. The appearance of cracks on the conversion coating surface may be resulted from dehydrating in the process of desiccation. The conversion coating is a kind of coating that hinders the contact between corrosion medium and matrix metal and inhibits the diffusion of corrosion products.

By means of free corrosion potential measurement, potentiodynamic and electrochemical impedance spectroscopy etc, the effect of fly ash and slag on corrosion behavior of reinforcing rebar was investigated in solution of cement extract with contaminant of chlorides, which was adopted to simulate the known concrete pore solution in reinforcements. The results show that fly ash and slag can effectively reduce the risk of chloride induced corrosion and the corrosion rate of reinforcing steel rebar. Besides, the threshold value of chloride for corrosion is increased to some extence. The inhibition ability to chloride induced corrosion is in the order of: slag > slag + fly ash > fly ash > cement. In addition, the corrosion inhibition efficiency of slag and fly ash decreases to some extent with the increase of the chloride concentration. The admixture of fly ash and slag at a appropriate proportion is excellent corrosion inhibitor for chloride induced corrosion to steel rebar in terms of cost and effectiveness.

Metal packaging is an industry sector of rapid development. However, the corrosion of metal cans caused by packaged corrosive drinks may shorten the service life of the cans. It was frequently seen that there were large area with corroded spots even perforations on the shrinkage area of the cans. To find out the causes of corrosion of metal cans and increase its corrosion resistance, a study on corrosion behavior of tinplates, color printing iron and filled cans was made in this paper using steady-state polarization curves and electrochemical impedance spectroscopy. The results indicated that the corrosion current density of the bare tinplate reach 40 μA/cm2, on the contrast, the corrosion current density of the passivated tinplate dropped nearly 10 times. The impedance measurement showed the same results. Electrochemical impedance test of real cans and color printing iron showed that the impedance values of filled cans dropped nearly 1000 times, compared to that of color printing iron, which revealed that after a series of can-making processes the performance of coating was detriorated significantly. It is suggested that the following measures may be the useful for improving the service life of metal cans: the passivation of tinplates or remedy of shrinkage parts of cans after making processes or application of coatings with performance much compatible to the making processes.

Corrosion performance of Ni-base alloys Incoloy800 and Incoloy840 after HNO₃ passivation treatment or application of SiO₂ coating was studied by potentiodynamic polarization test, XRD and SEM. The result showed that after HNO₃ passivation treatment the pitting potential and protection potential of Incoloy840 increased significantly, while Incoloy800 showed a few change in protection potential and little change in pitting potential. Flaw-less SiO₂ coating can be applied on the two alloys with TEOS and two surfactants (PEG200, PEG20000). The open-circuit potential and pitting potential of the two Ni-based alloys increased significantly after application of SiO₂ coating. Therefore, the corrosion resistance of the two Ni-based alloys may be significantly enhanced after surface treatments above.

The relationship of moisture and chloride ion content in Qingdao soil with the optimum cathodic protection potential for X70 steel was studied by electrochemical impedance spectroscopy(EIS)in a laboratory test set. The results revealed that the optimum cathodic protection potential increased firstly, then reduced with the increase of moisture content when chloride ion was less than 10 mmol/kg with a potential fluctuation about 150 mV. When the chloride ion is greater than 10 mmol/kg, the optimal protection potential showed a trend of reducing with increasing moisture content. The optimal cathodic protection potential in soil with various moisture contents reached a minimum for chloride ion content of 20 mmol/kg. With the rise of moisture content, the influence of chloride ion decreased gradually.

After a rutine inspection for a failured condensate/heavy diesel oil heat exchanger in a refinery in Algeria, it followed that the tube bundle of that set was suffered from serious erosion corrosion. The erosion occurred at the location opposite to the heavy diesel oil inlet. On the top surface of the tubes corrosion spots were observed, while corrosion products attached on the bottom surface of these tubes. Metallography, scanning electron microscope (SEM), energy dispersive spectrum (EDS) and electrochemistry tests were conducted to investigate the reason of this erosion corrosion, as well as the effect of heat treatment on the erosion resistance of TP405 tube bundle. Then solutions for this corrosion were proposed to avoid such kind of damage in the future.

After 8 years operation, a clapboard in water box of high pressure heater experienced perforation corrosion in a nuclear power plant. The structure, water chemistry and material of the water box are analyzed so that to trace out the mechanism of corrosion failure. In the meanwhile, the finite element method is used to ascertain the factors influencing corrosion failure. At last, the reason for failure is given, which is flow accelerated corrosion.