In fact, the metallic material corrosion process may intrinsically involve subprocesses such as the exchange of valence electron between metallic atoms and ions in corrosive medium, the formation of oxide scale, the migration of corrosive species through the formed oxide scale, and the interaction between oxidation scale and corrosive medium. Therefore, the energy state of the valence electron of components of metallic material may play an important role in the corrosion process, thus for reveal which, ultraviolet photoelectron spectroscope (UPS) and X-ray photoelectron spectroscope (XPS) may become useful tool. Herewith new progress in this respect is subsequently introduced. The valence electron energy state of components for bulk nanocrystalline materials 304 stainless steel (BN-SS304), industrial pure aluminum (BN-Al) and ingot iron (BNII), as well as their counterparts of conventional microcrystalline ones (CP-SS304), (CP-Al) and (CPII) was characterized by UPS at room temperature. The valence electron energy state of components of the oxide scale formed on these metallic materials due to corrosion in hydrochloric acid solutions, and the oxide scales formed on BN-SS304 and CP-SS304 due to air oxidation at 900 ℃ were comparatively studied by XPS. The above aquired results may enable one to establish the relationship between the corrosion performance with the valence electron energy state of components of these metallic materials, and to figure the electron structure of components of the corresponding formed oxide scales, as well. Furthermore, a new concept of intrinsic parameter related with metallic material corrosion was proposed.

The electrochemical behavior of three solvent-free epoxy coatings on Q345E carbon steel during corrosion-erosion induced by flowing slurry of simulated sea water with 1% (mass fraction) of sand at 60 ℃ was investigated by means of electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM) and confocal laser scanning microscopy (CLSM), respectively. The results showed that the flowing slurry induced erosion aggravated the deterioration of coatings. The amine-cured epoxy powder coating and phenolic aldehyde amine-cured liquid epoxy coating were cured with slow speed and thus much densified, accordingly, their deterioration process experienced three stages: firstly, the inward migration of corrosive medium; secondly, the corrosion initiation of the substrate metal; thirdly, the corrosion propagation of the substrate metal beneath the coating and finally the failure of coatings. On the contrary, the phenolic aldehyde-cured epoxy powder coating was cured with fast speed and thus much porous, its deterioration process experienced two stages with a shortened second stage. Therefore,the existence of pores in the coating is one of the important factors for inducing failure of coatings during corrosion-erosion.

The copper phthalocyanine disulfonic acid CuPc-(SO₃H)₂ (CuPANI) was prepared with direct fast turquoise blue GL as raw material, and then the CuPANI doped polyaniline was obtained by chemical reaction of eigenstate polyaniline (EBPANI) with CuPc-(SO₃H)₂ in N,N′-dimethylformamide. The doped polyaniline was characterization by IR, UV-Vis and four point probe. The coatings with EBPANI or CuPANI as filler and epoxy resin 44 (EP-44) and 107 glue as adhesives were prepared on the surface of pretreated steel sheets, while the corrosion behavior of the sheets without and with coatings with EBPANI and CuPANI in 3.5%NaCl solution was investigated by electrochemical methods such as tafel polarization curve measurement, and alternating current impedance spectroscopy, respectively. The results indicated that the CuPANI doped polyaniline coating shows better anticorrosion performance.

The evolution of corrosion product film formed on X80 pipeline steel in artificial solution,which simulate the soil medium at Ku'erle area, with different immersion time was studied by immersion tests, while the morphology and phase constituent of the corrosion product film was characterized by means of scanning electron microscope (SEM) and X-ray diffraction (XRD) respectively. The effect of corrosion product film on the pitting corrosion of X80 pipeline steel was investigated by cyclic polarization curves and electrochemical impedance spectroscopy (EIS). The experimental results showed that the thickness and compactness of corrosion product film gradually increased with increasing immersion time. After immersion for 168 h, the corrosion product film was clearly divided into two layers. The pitting of X80 pipeline steel may be hindered or inhibited by the corrosion product film, which may reduce the probability of pitting initiation, and increase the resistance to pitting growth.

The effect of sulfate reducing bacteria (SRB) on stress corrosion cracking (SCC) behavior of X100 pipeline steel was investigated in artificial solution, which simulated the acid soil medium in the area of Yingtan at the Southeast China by means of slow strain rate test (SSRT) and scanning electron microscope (SEM). The results show that X100 pipeline steel has higher SCC susceptibility in the sterile artificial solution than that with SRB. The failure mode is transgranular cracking in both the two solutions. These results suggest that SRB inhibits the brittleness and reduces the SCC susceptibility of X100 pipeline steel, which may be ascribed to that SRB can breed rapidly and form a compact biofilm on X100 pipeline steel surface, then partly block the migration of corrosive Cl^- onto the X100 steel surface.

Stainlesssteel 304 is being widely used in water supply system, and the dissolution of Cr⁶⁺ from materials of the system into tap water is one of the critical indexes of safety assessment. In the present work, different samples of stainless steel 304 components such as pipe, bar, plate, casting, and powder metallurgical product, were immersed in simulated tap water for 22 d, then the concentration of the dissolved Cr⁶⁺ in the water was determined by means of colorimetric of diphenylcarbazide with a spectrophotometer V-1800PC, while the microstructure of the samples before and after test was carefully examined by means of metallographic microscope MEF4A with image analysis system Q500 and SEM interms of morphology of grains, phase composition and distribution of inclusions etc. The results showed that the amount of dissolved Cr⁶⁺ versus time were quite different for sample to samples. The larger diameter and quantity of spherical inclusions in steels would be much favorable to the dissolution of Cr⁶⁺ for the same immersion period. In general, the spherical inclusions were complex oxides rich in Cr and Mn. In order to reveal the effect of MnO₂ on the dissolution of Cr⁶⁺ from the steel, artificial inclusions of Cr₂O₃ and Cr₂O₃+MnO₂ were introduced respectively into the steel by powder metallurgy, therewith the immersion test results showed that the dissolution of Cr⁶⁺ increased with the increasing amount of Cr₂O₃ and MnO₂. These results confirm that the inclusions of Cr/Mn complex oxides play important role in the dissolution process of Cr⁶⁺, i.e. they are not only the source of Cr³⁺, but act also as oxidant to transform Cr³⁺ to Cr⁶⁺ in the Cl^- contained solution. It can be inspired from these results that the Cr⁶⁺ dissolution could be significantly decreased by controlling the density and size of Cr/Mn oxides inclusions.

The corrosion behavior of the boiler tail material which is made of carbon steel and stainless steel in solutions of ammonium bisulfate (ABS) and H₂SO₄ respectively was studied by means of mass loss measurement and potentiodynamic polarization curve as well as SEM/EDS and XPS. The results showed that: stainless steel has better corrosion resistance to ABS, and with the increase of ABS solution concentration, corrosion becomes more intensive. The corrosion products consist of Fe₂O₃, FeOOH, Fe₃O₄, iron sulfate and a small amount of iron carbon oxide. The corrosion process of carbon steel and stainless steel is similar in the solutions with the same concentration of ABS and sulfuric acid. It can be concluded that ABS has stronger corrosivity. The corrosion mechanism is that hydrogen depolarization first may occur during the corrosion of carbon steel, and then generate hydrogen. As the acid consumption, as well as the effect of dissolved oxygen in the solution, the oxygen depolarization corrosion will happen on metal surface, Fe²⁺ is then further oxidized to Fe³⁺, produces a series of secondary reaction, to generate iron oxide and sulfate, etc.

The explosion of boiler tubes induced by the oxide scale causes a great influence on the safety and economy of power plants. The source of corrosion products in supercritical power plants is analyzed based on the physical and chemical properties of supercritical water, while the moving process of corrosion products can be described as follows: the corrosion products generated in the low pressure heaters and high pressure heaters, and then they are moving with the water. As the solubility of the corrosion products in the water was changed, which depended on both the pH and temperature, therewith the corrosion products deposit on the high temperature tubes. It follows from the analysis that the oxide scales on the boiler wall seem to be from two origins: the one is the high temperature corrosion of the tube wall itself, the other one is the deposition of corrosion products from upstream. Furthermore, the effect of the moving of corrosion products on the operation of power unit may be modified by properly inducing feed water of high quality in the steam-water system, thereby to ensure the safe and stable operation of the supercritical power unit.

The corrosion behavior of pure aluminum A1060 in tropic marine environment was simulated by cyclic immersion test, while the correlation of the corresponding results of indoor cyclic immersion test and outdoor marine atmospheric corrosion test of A1060 was comparatively studied in terms of its corrosion morphology, corrosion products and corrosion kinetics by means of weight loss measurement scanning, electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The results showed that the corrosion morphologies and phase constituents compositions of corrosion products after cyclic immersion test agreed fairly well with those after the real atmospheric test. Thereafter, a prediction model for the C corrosion prediction model of aluminum 1060 in two kinds of marine atmospheric environments, which aims to simulate the atmospheric environments at Wanning and Xisha areas in the South China Sea, was established built combined with Grey correlation method, while the corresponding arithmetic expressions could be described as follows i.e. T_WN=146.7t ^1.29 and T_XS=862.3t ^0.85 respectively.

The anti-corrosion performance of glass fiber reinforced plastic (GFRP) composites was evaluated by immersion test in 3.5% (mass fraction) sea salt solutions at 70 ℃ in terms of the decreasing trend of the pH value of the solution, the mass variation rate, and the bending strength retention rate of GFRP composites with time. While the surface morphology of the fractured surface of the composites, especially the glass fiber/resin interface before and after corrosion was examined by SEM. The concrete sample wrapped with GFRP composites was used to examine the time when Cl^- penetrated through the GFRP layer. And, the life of resistance to Cl^- penetration of 2 mm thick GFRP composites was predicted. Results showed that the life of resistance to Cl^- penetration for the unsaturated ester based GFRP composite was about 30 a; while the epoxy vinyl ester based GFRP composite was about 70 a.

The microstructure and mechanical properties of the seawater corrosion resistant rebar steel 00Cr10MoV was investigated, while its corrosion resistance was studied by salt-spray test, periodical immersion test, electrochemical impedance spectroscopy and polarization curve measurements. The results show that the microstructure of 00Cr10MoV composed of ferrite and bainite with yield strength above 400 MPa. Compared with 20MnSiV, 00Cr10MoV had excellent corrosion resistance in simulated marine environment. The charge-transfer resistance of 00Cr10MoV was 1.37×10⁵ Ωcm², 100 times more than 20MnSiV. Its corrosion products consist of major phases α-FeOOH, β-FeOOH and γ-FeOOH, minor phase Fe₃O₄ and trace phases Na₃CrCl₁₆ and Fe+3O(OH, Cl).

Original corrosion data, which were acquired by online detecting a buried oil and gas pipeline, were processed in accord with the Gumbel extreme value type I distribution, then a model for predicting the maximum corrosion depth is built to determine the possible maximum corrosion depth of the whole pipeline with the above method, a model for predicting the residual thickness of pipe wall is established to predict the residual life of oil and gas pipelines. In the end, as an example, the model was used to predict the residual life of a domestic pipeline in service, it is ca 19.95 a, which indicates that the predict result is correct and reasonable.

The influence of short-term storage in dry atmosphere on the corrosion behavior of copper was investigated by means of potentiodynamic polarization, electrochemical impedance spectroscopy, capacitance measurement and array electrode technique. It was found that the surface film on copper presented a p-type semiconductor structure, and the carrier concentration decreased after short-term storage. At the same time, the corrosion potential increased, the corrosion current density decreased, and the surface film inhibited both the cathodic and anodic process. Copper displayed the typical characteristics of localized corrosion beneath a NaCl droplet. After storage, the wet-ability, the corrosion activity as well as the overall average corrosion intensity are reduced, but the local corrosion intensity enhanced.