The present state of the environmentally assisted cracking (EAC) of the welded structural metallic materials for light water reactor (LWR) nuclear power plants was reviewed. Three factors affecting the EAC of the welded metallic materials were taken into account, including corrosive environments, susceptible materials and stresses. Several EAC mechanisms and EAC involved design models are discussed. The coming possible research topics and directions in this area are also proposed.

Alternate immersion and dry test, neutral salt spray test and electrochemical measurement were employed to investigate the weather-resistant performance of the imported S355J2W steel for CRH3 EMU (electric multiple unit) frame and SMA490BW steel for CRH2 EMU frame, respectively. The domestic Q235 steel was selected as the reference in the study. The results showed that the weather-resistant behavior of S355J2W and SMA490BW steel was different in the three corrosion tests. The corrosion rate of SMA490BW in alternate immersion and dry test was lower than that of S355J2W steel due to its higher content of Cu and Cr. While the S355J2W steel exhibited the better corrosion properties in neutral NaCl solution, which indicated that the steel is much more suitable for the application in coastal environment.

In order to develop a simple, fast, and reliable technology for corrosion monitoring for metallic materials in marine environment, the reliability of two electrochemical methods, constant current charging method and slightly triangular wave methodwere comparatively examined for the corrosion process of Q235 carbon steel in seawater. The results indicate that the two methods can monitor the corrosion of carbon steel in seawater well; cathodic polarization is recommended for constant current charging method, and the plused constant current density is -3 or -5 μA/cm²; cathodic polarization is recommended for slightly triangular wave method, and the scan rate is 0.1 or 0.2 mV/s.

The effect of erosion fungus on surface morphology and protective performance of A04-60 amino paint was studied by using fungus test, scanning electron microscopy (SEM), atomic force microscope (AFM) and electrochemical imepdance spectroscopy (EIS). Results show that deterioration of A04-60 amino paint is mainly caused by Aspergillus niger strains, due to the action of which the surface of the coating became rougher, surface defects on the surface were constantly expanded and deepen, therefore the impedance and protectiveness of the A04-60 amino paint decresed.

Air batteries consisted of pure Al, pure Zn and Al-5Zn-0.02In-1Mg-0.05Ti as anode respectively and with 0.6 mol/L NaCl solution as electrolyte were prepared and then their performance was comparatively evaluated by discharge test. Whilst the corrosion behavior of pure Al, pure Zn and Al-5Zn-0.02In-1Mg-0.05Ti was studied by measurements of free-corrosion potential and corrosion rate, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). The characteristics of Al-5Zn-0.02In-1Mg-0.05Ti alloy after discharge were examined by scanning electron microscopy (SEM). The results show that the air battery based on Al-5Zn-0.02In-1Mg-0.05Ti alloy offers higher operating voltage, anodic utilization efficiency and electric capacity rather than those with Al and Zn. The free-corrosion rates of the three materials can be ranked as Al<Al-5Zn-0.02In-1Mg-0.05Ti<Zn. SEM and EIS results show that small and shallow pits distribute uniformly on the discharged surface of Al-5Zn-0.02In-1Mg-0.05Ti alloy, and thus the alloy could keep high discharge activity during discharge.

The corrosion inhibition of Gemini surfactant (DBA_2-12) for N80 steel in 1 mol/L HCl was investigated using mass loss methods, electrochemical methods and scanning electron microscopic methods. It was found that DBA_2-12 exhibited good corrosion inhibition performance. Mass loss method reveals that the inhibition efficiency increases with the increase in concentration of DBA_2-12, while decreases with the increase in temperature of acid medium. The adsorption of DBA_2-12 on the metal surface has been found to obey Langmuir isotherm. Potentiodynamic polarization studies clearly suggest that DBA_2-12 acts as mixed-type inhibitor, which can be adsorbed on N80 steel surface, leading to the formation of a protective film to decrease the corrosion rate.
Key words: gemini surfactant, corrosion inhibitor, electrochemical, N80 steel, Langmuir
isotherm

A WC/Co coating was prepared on cast iron by plasma spraying, and the corrosion behavior of which was examined by neutral salt spray test. The surface morphology, microstructure and composition of the WC/Co coating were characterized with SEM, EDS and XRD before and after corrosion test. The results show that WC/Co coatingconsisted mainly of W₂C and C, and after salt spray corrosion the phase constituent of the coating is not changed. During salt spay test, cast iron is seriously corroded with the type of mainly general corrosion and stress corrosion, while the WC/Co coating is slightly corrodedwith the type of mainlyselective corrosion and partially stress corrosion. The corrosion resistance of WC/Co coating is far superior to cast iron, thus can enhance the resistance of cast iron to salt spray corrosion effectively.

A novel etching process of indium tin oxide (ITO) transparent electrode and its etching effect were reported. Etching liquid was made up of FeCl₃ solution with various pH as functional component, PEG10000 as medium, and gas phase SiO₂ as thixotropic agent. ITO etching experiments were carried out by screen printing method. The influence of different etching conditions on ITO electrode volume resistivity was studied. The result shows that the optimal etching condition is etching at 80 ℃ for 90 min in a solution with pH 1.67. The change of composition and morphology of ITO electrode was characterized by EDS and AFM respectively.

Intergranular corrosion behavior of 304H stainless steel in H₂SO₄-CuSO₄ solution was examined according to GB/T 4334-2008 so that to reveal the sensitization of the steel with test temperature and time. OM, SEM and EDS techniques were adopted to observe the carbides precipitation at grain-boundary and analysis measurement image software was applied to measure the width of grain-boundary. The aging precipitation kinetics was analyzed according to Avrami empirical equation. It was found that specimens aged at temperature range 600 to 750 ℃ were sensitized obviously and 650 ℃ was the most sensitive temperature. The quantity and size of precipitated carbides were both increased with increasing aging time at a given temperature, While for a given aging time the precipitated carbides at grain-boundaries increased first and then decreased until 850 ℃. The same regulation could be verified with the isothermal precipitation kinetics curve and the change of grain-boundary width at 650 ℃ for 10 h aging treatment.

The corrosion behavior of 254SMo and TP317L stainless steels in the primary and secondary water of papermaking intermediate waters was investigated with electrochemical tests and electron-microscope (EM) technique. This aims to provide the basis for material selection of the condenser of a new 600 MW heating unit. The results show that Cl^- promoted the pitting corrosion of 254SMo and TP317L in papermaking intermediate waters; under the same water quality condition, the corrosion resistance of TP317L in primary water is better than that in secondary water, 254SMo just the reverse. Whether in primary water or secondary water, 254SMo shows much excellent resistance to pitting corrosion rather than TP317L.

The corrosion of the hot water supply system in a thermal power plant in Baotou was analyzed.Results showed that corrosion of the inner surface of pipe was oxygen corrosion,the main influencing factor were DO (dissolved oxygen) and pH value.In order to solve the corrosion problem, a new compound corrosion inhibitor with Sodium erythorbate as the main component was proposed. Due to synergistic effect exists amongthe components of the compound ihibitor, therefore, the inhibitor can effectively enhance the resistance of the steel pipesto the corrosive softened waterin the system. The corrosion rate of carbon steel may be lowered to only 0.0303 mm/a with a dose of 150 mg/L inhibitor for the soften water with pH 10.