The paper summarized the anomalous deformation characteristics, influencing factors and mechanisms of dynamic strain aging (DSA) in nuclear-grade carbon steels, low alloy steels and austenitic stainless steels. The possible effects of the interaction between DSA and high temperature water on environmentally assisted cracking of structural materials used in nuclear power plants have been discussed. The coming possible research topics and directions are also proposed.

Zinc-nickel alloy coatings were electroplated from an alkaline electrolyte using direct current, the influences of principal technological parameters on the composition of zinc-nickel alloy coatings were studied using energy dispersive spectrometer (EDS). The results show that the content of nickel in Zn-Ni deposits kept between 11% and 13% and the co-deposition of zinc and nickel behaved anomalously. The microstructure of the optimized deposition was characterized by scanning transmission electron microscope (SEM), atomic force microscope (AFM) and X-ray diffractometer (XRD), the results showed that the Zn-Ni deposits consisted mainly of the γ-phase(NiZn₃) and the film was compact and fine-grained. Meanwhile, the Tafel plot measurements proved the coating had good corrosion resistance.

The electrochemical behavior of 300M and a new kind of ultra high strength steel (Cr9 for short) in sulfate acidic environment, as well as the effects of pH and Cl^- concentration on the corrosion behavior were studied by potentiodynamic polarization curve, EIS, and metallographic microscope. The results showed that with increasing pH value, the corrosion potentials E_corr of 300M and Cr9 shifted towards the positive direction, the charge-transfer resistances R_ct increased, and the corrosion current densities em_corr decreased. The (H₂SO₄+Na₂SO₄) solution with decreasing pH value suppressed the corrosion rates of 300M and Cr9. In the chloride-free sulfate acidic solution, general corrosion on the 300M surface occurred, while on Cr9 surface pitting occurred. The addition of chloride ions induced the pittings and transformed the passivity of Cr9 into an active dissolution state. Cr9 steel contains more contents of Cr, Mo and Ni, and the elements enhanced the corrosion resistance in acidic solution and made a much lower corrosion rate compared with 300M.

Vinyltriethoxysilane films doped with cerium nitrate (Ce(NO₃)₃) were prepared on the surfaces of Q235 steel. The optimum addition level of cerium nitrate was studied by electrochemical impedance spectroscopy (EIS). The corrosion resistance of Q235 steel coated by the doped silane films during immersion in the aqueous solution of 3.5% NaCl was investigated by electrochemical impedance spectroscopy (EIS) and by the potentiodynamic polarization. Scanning electron microscope (SEM) was used to observe the morphology of surface of the doped silane films. The results showed that the optimum addition level of Ce(NO₃)₃ is 1×10^-3 mol/L. The anode reaction and the cathode reaction on the interface of Q235 steel coated by the doped silane films during the corrosion were restrained. The corrosion current density of the Q235 steel coated with the doped silane films decreases by almost three orders of magnitude and its polarization resistance increases by about three orders of magnitude as well as its low-frequency impedance increases by more than four orders of magnitude when compared with those of the blank steel sheets during immersion in 3.5% NaCl aqueous solution.

The experiment invested the effect of soluble salts content of substrate surface on the anti-corrosive properties of the coating by GB/T 10834-2008 and ASTM D870-02 standards, and corrosion results were evaluated according to the GB/T 1766-2008 specification. Besides, the morphologies of the coating after immerged were observed by SEM. The result shows that the time order of visible damage of the coating is blistering, flaking and rusting respectively. It is more permeative of the deionized water used by ASTM standard than the salt water used by GB due to the existence of soluble salt on the matrix, which has great attack on the coating. The range of soluble salt changes from 28.02 mg/m² to 43.92 mg/m², which makes the coating damage dramatically, so we think the threshold value is about 43.92 mg/m².

The effect of negative potential of bipolar pulse on the compactness of plasma electrolytic oxidation (PEO) coating on magnesium alloy is not definite nowadays. PEO coatings on magnesium alloy AZ31B were prepared by respectively using unipolar and bipolar pulse whose negative potential was changed while positive potential was at several levels. In order to analyze the effect of negative potential on compactness of PEO coatings, the samples were examined by electrochemical impedance spectrum (EIS) and scanning electron microscope (SEM) to study the variation of equivalent circuit data and the change of macrostructure. The results have shown that negative potential plays an important role on compactness of PEO coatings and suitable negative potential can increase the compactness of coatings. The negative potential of pulse which can prepare compact coatings is always 30 V and stays the same at several levels of positive potential.

Cr₂O₃ coating was deposited on Q235 steel by means of plasma-sprayed technology, which was sealed by aluminum phosphate and epoxy resin respectively. The porosity of the coating was investigated by graph analysis and electrochemical measurement, and the corrosion resistance of the coating was characterized by polarization curve and electrochemical impedance spectroscopy (EIS). It is found that the sealing treatment can elevate corrosion resistance of the Cr₂O₃ coating. Compared with the coating sealed with aluminum phosphate, the epoxy resin-sealed coating shows excellent corrosion resistance. The electrochemical behavior of the Cr₂O₃ coating in the corrosive electrolyte depends mainly on the porosity of the coating.

Corrosion weight loss, polarization techniques, electrochemical impedance spectroscopy(EIS) and corrosion morphology were used to estimate the impact of Sb addition on corrosion properties of Mg-5Al-2Sr alloys in 3.5% NaCl solution. Experimental results show that the initial corrosion types of Mg-5Al-2Sr-xSb(x=0, 0.3, 0.6, 1.0) alloy in 3.5% NaCl solution is pitting corrosion. Pitting originated in massive ternary τ phase and granular SbSr₂ phase. The larger amount and the bigger size of these phases corresponds to the poorer resistance. Mesh distribution Al₄Sr phase can become an effective barrier of corrosion. Adding 0.3% Sb not only refines the α-Mg matrix of Mg-5Al-2Sr alloy, but also promotes the formation of Al₄Sr phase which distributed more in network. The corrosion potential of the alloy shifts positive obviously, the corrosion current density and corrosion rate reduces, thus, the corrosion resistance of the alloy is improved.

MWCNT/TiO₂ composite film was prepared on the surface of the 304 stainless steel by the sol-gel technology and spin coating method. The phase and morphology of the composite film were measured by the X-ray diffraction and the electron microscope. The photocathodic properties of the composite film for the 304 stainless steel under UV and white light were analyzed by the electrochemical tests. The results indicated that the composite film containing the carbon nanotubes with the size of 20~40 nm and heated under 450℃ has the better photoelectric property either irradiated by UV light or white light corresponding to that of pure TiO₂ film. At the same time, it was also indicated that the addition of MWCNT into TiO₂ film could enhance the photocathodic property for 304 stainless steel either in 3% NaCl solution or in the seawater.

The influence of aluminium content on the corrosion behavior of superplastic Zn-Al alloys immersed in simulated acid rain was investigated. The results showed that, the corrosion behavior of the Zn-Al alloy in simulated acid rain solution was related to the microstructure of the alloy. Al-rich phase was prone to preferential attack, but the corrosion rate of the alloy was decreased with the aluminum content of the alloys increases. There was a discontinuous Al-rich phase distributed on the grain boundaries of ZA4 alloy and ZA8 alloy, the corrosion products were loose and the corrosion pits were deeper, that resulted in a relatively high corrosion rate, whereas the corrosion reaction can be effectively blocked by the continuous distribution of Al-rich phase of ZA12 alloy and ZA16 alloy.

Effect of aging treatment on electrochemical corrosion of 2205 duplex stainless steel (DDS) in 3.5% NaCl and (1, 5, 10) g/L S solution were studied by potentio-dynamic scanning (PDS) and electrochemical impendence spectroscopy (EIS). The research shows that the σ-phase was precipitated at the γ/α interfaces after aging treatment(800℃), it has a harmful effect on the corrosion of 2205 DDS. The corrosion rate of 2205 DDS increases with the amount of σ-phase, which increases with aging time. Besides, it also promotes the corrosion rate of 2205 DDS with adding sulfur.

This paper discussed the influence of pulse parameters (pulse height, pulse width and reverse pulse variables) on the phosphorous content and morphology of Ni-P coatings. The result showed that both average current density and reverse anodic current density had a strong effect on the phosphorous content, whereas duty circle and frequency had great impact on the morphology of coatings. Compared with the Ni-P coatings prepared via direct current electrodeposition, pulse plating method increases the content of phosphorous without changing the composition of the solution.

A phosphate solution, free of chromate, fluorides and nitrite, was prepared to form the corrosion resistance conversion film on the AZ31 magnesium alloy surface via chemical deposition, and the effects of film-forming temperature and free acid on surface morphology and corrosion resistance of the film were investigated via CuSO₄ pitting corrosion test, scanning electron microscopy and potentiodynamic polarization curves. The denser film with grain of 20 μm, whose time of CuSO₄ pitting corrosion resistance is longer than 5 min, is obtained on the following process: film-forming temperature 95℃, FA 4~5, ratio of TA/FA 15~20. The E_corr with the film is shifted positively 110 mV(vs. SCE), the I_corr is decreased approximately by three orders compared with that of the bare substrate AZ31 respectively. The results show also that the existence of the film has a great inhibitive action on anodic dissolution and restraint action on the cathodic hydrogen evolution. The dense film is not obtained when the film-forming temperature is lower than 75℃, but increasing with the film-forming temperature, the grain is refiner and the film is denser, which can improve corrosion resistance performance of AZ31 magnesium alloy. Unfortunately, higher film-forming temperature is easy to accelerate hydrolysis of the phosphate and cause plenty of residues phosphide. But the decreasing of residues phosphide can be effectively controlled by controlling the adding amount of the free acid, which further improve quality of the film and decrease the cost.

The corrosion resisting property of four corrosion inhibitors in HCl on mild steel, including 2-methyl-5-hexylisoxazolidine (A), 2-methyl-5-dodecylisoxazolidine (B), 2-isopropyl-5-dodecylisoxazolidine (C) and 2-tert-butyl-5-dodecylisoxazolidine (D), was theoretically evaluated using quantum chemistry calculations and molecular dynamics simulations. The corrosion inhibition mechanism was analyzed. The quantum chemical calculations indicated that the frontier orbitals of four molecules were located in the isoxazole ring and side chain of the molecules. The electrophilic attack centers of the inhibitors were on the N and O atoms. Molecular dynamics calculation shows that under liquid conditions the polarity head group of isoxazolidine corrosion inhibitors priority adsorbed in the metal surface, while the alkyl chain stayed in the water phase with distortion. The strength of molecules adsorbed on the surface enhanced with increasing the number of methyl in the molecular heads. The theoretical evaluation was shown to be in complete accord with experiment results.

Forming of ceramic coatings on surface of ZAlSi2Cu2Mg1 by micro-arc oxidization (MAO) in a Na₂SiO₃ electrolyte was investigated. The influences of content of NaOH on the conductivity of electrolytes, arc starting voltage, thicknesses of ceramic coatings, and morphology of coatings were analyzed respectively. Phase compositions of coatings were analyzed by XRD. The results show that while content of NaOH rises from 1.0 g/L to 3.0 g/L, the conductivity of electrolytes rises from 4.00 ms/cm to 26.28 ms/cm, and arc starting voltage decreases from 360 to 290 V. While the content of NaOH rises from 1.0 g/L to 2.5 g/L, the thickness of coatings increase gradually from 92 to 125 μm. But as the content of NaOH exceeds 2.5 g/L, the thickness and the proportion of compact layer decreases. The XRD result indicated that the coatings are composed of mullite, SiO₂, α-Al₂O₃, γ-Al₂O₃ and WO₃.