The resistance to corrosion of a MnCu cost-effective weathering steel under cyclic loading in a simulated chloride ion environment was investigated. The experiments were performed using a new wet/dry cyclic corrosion test (CCT). In order to simulate wet and dry alternative corrosion, 0.3 mass% NaCl solutions was sprayed on the specimens which were tensioned in the range of elastic deformation under cyclic loading (the maximum stress was 208 MPa). The rusted specimens were examined by SEM and via electrochemical measurements. The results showed that, in the same cyclic tension period, the MnCu cost-effective weathering steel has stable rust layer after low CCT, but there were more cracks appeared in outer rust layer after higher CCT due to the cyclic loading, but MnCu cost-effective weathering steel had still excellent corrosion resistance, because the inner rust played a key role to resist further corrosion.

Effects of trace rare earth (RE) elements on microstructure and mechanical properties of HAl77-2 Al-brass were analyzed by OM and conventional mechanical test. Static corrosion experiment was used to study the corrosion behavior of the Al-brass after adding RE addition and SEM, energy analysis and XRD were simultaneously used to investigate the corrosion product layer synthetically. It was demonstrated that adding RE to Al-brass could refine grain and increase strength, but decrease the elongation; The corrosion resistance of the RE-containing Al-brass was better than that of Al-brass without RE in NaCl (3.5 mass%) solution. The consequence of such good corrosion resistance was attributed to the formation of compact protective film on alloy surface which contained RE elements. The RE-contained film, which was composed of an inner Al₂O₃, RE oxide and an outer chloride or basic chloride of Cu, Zn, combined with the matrix firmly and was difficult to fall off from the alloy surface. While the addition of RE could not improve the corrosion resistance of Al-brass. in NaCl (3.5 mass%) +S^2- solution. Although the corrosion products layer was ameliorated due to the RE addition, the corrosion resistance of the alloy deteriorated yet owing to the severe embrittlement of the corrosion product layer caused by Cu₂S.

Hydrogen-induced fish-scaling resistance got better as hydrogen diffusion coefficient of enamelled steel sheet D decreased, which is inversely proportional with the TH value. The main objective of this work was to study the effects of certain variables such as nickel-plating or not, sample thickness, promoter concentration and charging current on TH value. The results showed that no-nickel-plating for sample surface did not influence the stability of TH value. If sample thickness d increased from 0.25 mm to 0.6 mm, TH value decreased linearly. TH value kept invariant when d ≥ 0.6 mm. TH value decreased with the increase of charging current density and promoter concentration.

The diffusivity of point defects in the passive film formed on 2205 duplex stainless steel and 316L stainless steel in NaCl solution was calculated by means of capacitance measurement and PDM (point defect model). The calculated result was testified and analyzed by experimental steady current density of passive film and PDM. It is showed that the order of magnitude of diffusivity is about 10^-23  cm²/s~10^-20 cm²/s, and the diffusivity of 2205 DSS is less than 316L SS in simulated ocean solution. It is concluded that the diffusion of point defect which is caused by oxygen vacancy in 2205 DSS is harder than 316L SS, so in contrast to 316L SS, the passive film of 2205 DSS is much densified and compact with completeness and excellent protection.

The inhibition of corrosion of mild steel in 1 mol/L HCl by 1-phenyl-3-methyl-5-pyrazolone (PMP) and 1-phenyl-3-carbethoxy-5-pyrazolone (PCP) was investigated by using mass loss experiment and quantum chemical method: semi-empirical PM3 and density functional theory (DFT) method 6-31G*. The results of mass loss test showed that the highest inhibition efficiency of PMP and PCP reached 93% and 91% respectively at 1.0×10^-3 mol/L. A linear fit to Langmuir isotherm was obtained between C/θ and C. Quantum chemical parameters such as highest occupied molecular orbital energy (E_HOMO), lowest unoccupied molecular orbital energy (E_LUMO), energy gap (ΔE) and dipole moment (μ) have been calculated for these compounds by using semi-empirical PM3 and 6-31G*. The lone electron pair of the nitrogen atom and the π-electrons of the phenyl make it possible to form coordination bond with iron surface.

The chemical oxidative method was applied to prepare the eigenstate polyaniline (PANI) and hydrofluoric acid doped PANI, whose structure was characterized by FT-IR. Epoxy resin was used as the film-forming substance and to prepare the eigenstate PANI and hydrofluoric acid doped PANI/epoxy coating on AZ91D magnesium alloy surface, and their anti-corrosion properties were studied by means of electrochemical impedance spectroscopy (EIS) in 3.5% NaCl solution. The surface morphology of AZ91D magnesium alloy after immersion was observed by SEM. The results indicated that the addition of eigenstate PANI could significantly improved the corrosion resistance of epoxy varnish coating. However, hydrofluoric acid doped PANI/epoxy coating had better corrosion resistance than eigenstate PANI/epoxy coating. XPS results indicated that the presence of polyaniline changed the chemical structure of the corrosion film on the alloy surface.

Corrosion deposites of super duplex stainless cast steel on surface after electrochemical polarization in arterial seawater were studied by X-ray photoelectron spectroscopy in this paper. The results indicate that the outside passive film of cast duplex stainless steel is mainly composed of CrO₃ and hydroxide type compounds such as CrOOH, Cr(OH)₃, Fe(OH)₃. The inside film is mainly composed of oxide such as CrO₃、Cr₂O₃, FeO, Ni₂O₃, and some elements of Fe, Cr, Ni, Mo as simple substance in it. MoO^2-₄$ and NM⁺₄ ions exist between passive film and solution which act fairly protective effect.

Modern testing techniques such as TEM, SEM, EDAX, Tafel curves, E-T curves and hydrogen collection test have been applied to analyze the effect of rolling temperature on the microstructure, electrochemical and anti-corrosion properties of Al-Mg-Sn-Bi-Ga-In alloy anode in alkaline solution （80℃, Na₂SnO₃+5 mol/L NaOH）. The results show that when controlling the pass deformation at 40\%, with the increase of rolling temperature, the microstructure of Al alloy anode undergoes a process from disordered dislocations cell structure, subgrain structure to dynamic recrystallized structure. When the rolling temperature is 420℃, the Al alloy anode has the most negative electrode potential of about -1.48 V（vs•Hg/HgO） and the lowest hydrogen evolution rate of 0.1716 mL•cm^-2•min^-1 due to the uniform distribution of active elements and decrease of segregation phases in alloy. The optimum comprehensive performance of Al alloy anode has been obtained.

Al-Mn alloy coatings were deposited on zinc pre-plated magnesium alloy AZ31B from a bath of inorganic molten salts. Then the microstructure, composition and phase constituents of the coatings were investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD). The corrosion and wear resistance of the coatings was evaluated by potentiodynamic polarization and microhardness measurements, respectively. The results indicated that the typical processing parameters such as composition of molten salts, cathode currency density and temperature had important effect on the morphology and chemical composition of the Al-Mn alloy, and the alloy coating with various composition present different phase constitution. It showed that the Al-Mn alloy coating exhibited a much higher corrosion potential and lower corrosion rate than that of Mg alloy AZ31B, so it can well protect the magnesium alloy AZ31B against corrosion.

The article discussed different statistical analyses and predictive models in the corrosion research, including linear regression model, gray model, artificial neural network and dose-response functions. The new social science predictive model-multilevel model was introduced. The hierarchical liner modeling (HLM) analysis model was always applied in social science. The article discussed the possibility of the multilevel model which would be applied in corrosion research.

The axial loading fatigue testing results show that the fatigue life of welded joints of BT20 titanium alloy decreased under the condition of salt fog, SO₂ and salt fog at different stress radio and stress concentration factor K _t=1. The loss of fatigue life was obvious in acidic of SO₂ and salt fog. As stress ratio R changsed from 0.5 to 0.06 at fatigue life N=10⁵, wet air made fatigue strength decreases 18%，salt fog made fatigue strength decreases 16%, SO₂ and salt fog made fatigue strength decreases 7%.

The effect of 0.2 mass% Yb/Dy additives on the oxidation resistance of Fe-20Cr alloy at 900℃ in air was studied, and EIS was used to investigate the electrical conductivity of oxide scales formed on the alloys at 900℃. Experimental results indicated that the addition of Yb and Dy to Fe-20Cr promoted the formation of a Cr-rich oxide scale, increased the adhesion of oxide scales, and thus improved its oxidation resistance, with a better effectiveness observed for the element Dy. Electrochemical impedance spectra for the oxidized Fe-20Cr-0.2Dy in neutral Na₂SO₄ solution bubbled with N₂ were composed of double capacitive loops, suggesting a two-layer structure of the films, however, which was not obviously observed from EIS of the oxidized Fe-20Cr and Fe-20Cr-0.2Yb. The lowest electrical conductivity was observed for the scales formed on Fe-20Cr-0.2Dy, indicating a better oxidation resistance, as confirmed by kinetic measurements. The capacitance and resistance obtained can be related to the thickness and defectiveness of oxide scales, so electrochemical impedance spectroscopy was a proper investigating method for the oxidation and corrosion of metal and the results of other analytical techniques were in agreement with the EIS data.

Different structures scales were formed on the surface of SS400 hot rolled strip with different cooling methods. Corrosion behaviors of hot rolled strip with different oxide scales were investigated in sodium bisulfite solution by SEM, EDS, XRD, accelerated cyclic wet-dry immersion corrosion test, polarization curves and electrochemical impedance spectroscopy (EIS). The results showed that three kinds of oxide scales prepared by different cooling methods mainly consisted of Fe₃O₄, as well as a spot of Fe₂O₃ and Fe. The content of Fe₃O₄ increased with cooling rate reducing, but FeO was not detected. Oxide scale prepared by furnace cooling on the strip consisted of the outer Fe₂O₃ layer and the inner Fe₃O₄+Fe layer, and its thickness was more thick and homogeneous than the rest scales. Oxide scale prepared by jar cooling was homogeneous, but that prepared by air cooling had a lot of defects. Corrosion resistance of strip prepared by furnace cooling was best in 0.01 mol/L sodium bisulfite solution, but that of strip prepared by air cooling was worst.

The electrochemical performance of Al-Ga binary alloy with different Ga content were evaluated by constant current test. And the activation mechanism was investigated by X-Ray, SEM+EDS and redeposit experiment. The results showed that Al-0.07%Ga welded by high purity aluminum and Al-0.1%Ga welded by Al99.85 exhibit suitable working potential as low driving voltage sacrificial anode for cathodic protection of high strength steel. Their working potential was varied from -820 mV~-876 mV, -802 mV~-818 mV (vs. Ag/AgCl seawater) respectively. However, their performance needs to be improved for its serious local dissolution morphology. The Ga content of corrosion product was increasing with increasing of the Ga content of anode matrix, but the latter is far greater than the former. The content of Ga in anode surface is increasing for Ga³⁺ redeposit to the surface. The activation mechanism of Al-Ga anode obeys dissolution-redeposit mechanism.

In order to clarify the influence of elemental Mn on corrosion resistance of weathering steel in solution simulating industrial atmosphere, EIS (electrochemical impedance spectrum) were measured and the obtained results were verified by EPMA (electron probe micro-analyzer). EIS tests showed that, at the early stage of corrosion, the weathering steel with high Mn content had a more remarkable pitting generation characteristic than the reference steel. At the late stage of corrosion, two experimental steels had comparable corrosion resistance. The result of EPMA proved that Cu and Cr were main contributors to form protective rust layer because they were enriched at the interface between inner rust layer and substrate but no enrichment of Mn in the rust was observed.

The oxidation behavior of a single crystal superalloy at 900℃ and 1000℃ in air was investigated by using discontinuous thermogravimetric analysis (TGA). The oxidized samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed the oxidation kinetics of the alloy at 900℃ and 1000℃ followed parabolic law basically. The oxidation resistance of the alloy at 900℃ and 1000℃ was the first grade, while the rate of oxidation at 1000℃ was higher than that at 900℃. The oxidation scales were composed of (Ni,Co)O prevalently. However, α-Al₂O₃, less Cr₂O₃ and complex oxides, such as CrTaO₄, (Ni,Co)Al₂O₄ and Co(Al,Cr)₂O₄ were found in the oxidation scales. The scales were layered with outer (Ni,Co)O layer and inner α-Al₂O₃ layer. The inner α-Al₂O₃ layer was continuous and dense and then provided good protection. Furthermore, there were nitride precipitates in the matrix of the alloy and close to the α-Al₂O₃ layer.