The effect of shot peening (SP) and stress on the exfoliation corrosion behaviour of 2E12 Al alloy was studied by means of exfoliation corrosion test, metallographic analysis, scanning electron microscopy (SEM) and XRD analysis. The results show that 2E12-T3 Al alloy has a high susceptibility to exfoliation corrosion (EXCO). Tensile stress reduces the resistance to EXCO while compressive stress improves it. Appropriate SP (intensity 0.15 mmN, coverage 100%) can significantly reduces the susceptibility of 2E12-T3 Al alloy to EXCO and suppresses the formation of blisters, which may be due to the refined grain size and residual compressive stress produced by SP treatment on the surface layer. However, SP with extra intensity or coverage can not improve the resistance to EXCO due to the seriously damaged alloy surface.

The effect of solution pH value and H₂S partial pressure on the electrochemical corrosion of P110 tubing steel in solutions containing dissolved H₂S/CO₂ in an autoclave, which aimed to simulate the annular service environment, was studied by electrochemical measurements, U-bent specimen immersion test and surface analysis technique. Results indicate that, with the increase of solution pH value and H₂S partial pressure, the corrosion current density of P110 tubing steel decreases significantly. H₂S partial pressure suppress the anode reaction of P110 tubing steel but enhance the cathode hydrogen permeation, which then promotes crack initiation and increases its stress corrosion susceptibility.

Based on the results of volatilization reduction test in a confined space and quantitative evaluation test, it follows that dimethyl imidazole is a kind of medium and long term anode type green volatile corrosion inhibitor, which is somewhat like the known phytic acid. However its corrosion inhibition is better than phytic acid's. Finally, an optimal formula as a volatile corrosion inhibitor of dimethyl imidazole coupled with other compounds is found and its effectiveness is also verified by experiments.

The galvanic corrosion in seawater for the couple of commercially pure titanium (TA2) and low alloying steel (921A) was studied under open circuit conditions by using potentiodynamic polarization measurements and a multi-pass zero-resistance ammeter (DL-1), and then the effect of elevated temperature was examined. The surface morphology of the tested samples was characterized by means of scanning electron microscopy (SEM with EDX) and X-ray diffraction (XRD). Results show that 921A acts as the anode and TA2 acts as the cathodes in galvanic couple. Galvanic corrosion process involves a higher rate of anodic dissolution for 921A and dissolved oxygen reduction reaction on cathodes. The strength of the galvanic coupling effect is typically controlled by the oxidation rate of 921A. The galvanic corrosion of TA2/921A increased with the increasing temperature. The galvanic current density is estimated to exponentially increase with increasing temperature.

Electrochemical methods of the potentiodynamic polarization and the electrochemical impedance spectroscopy were employed to investigate the corrosion behavior of J55 steels alloyed by combination of Cr and Al in the imitated high salinity brine of Changqing's oil well water. And the effect of the pre-corrosion on the corrosion process was thus examined. The open circuit potential of high Cr-Al alloy steel shifted to the positive direction comparing with J55 steel; the results of polarization curve show that the corrosion current density of high Cr-Al alloy steel decreased and its corrosion rate declined; the fitting results of electrochemical impedance spectroscopy indicate that its polarization resistance increased. After pre-corrosion, the corrosion product film of high Cr-Al alloy steel exhibited higher corrosion resistance significantly rather than J55 steel and then the corrosion rate decreased correspondingly.

The influence of Mn addition on corrosion behavior of Mg-9Al-2Sn-xMn (x=0, 0.1, 0.3) in 3.5% (mass fraction) NaCl solution was investigated. Corrosion rates of Mg-9Al-2Sn-xMn (x=0, 0.1, 0.3) were measured by means of immersion and hydrogen evolution tests. Whilst, the corrosion process and corrosion products of Mg-9Al-2Sn-xMn (x=0, 0.1, 0.3) were examined by means of electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The results showed that the addition of 0.1% Mn could decrease the corrosion rate of the alloys; and after addition of 0.3% Mn, their corrosion rates increased a little bit, yet which was smaller than rate of alloy without Mn addition. However, the addition of Mn didn't change the corrosion mechanism of the alloy Mg-9Al-2Sn.

Several inorganic additives were added into the electrolyte to improve surface properties of the ceramic coating produced by micro-arc oxidation process on aluminum alloy. The phase constituents and microstructure of the prepared MAO coating were characterized by means of X-ray diffractometer (XRD) and scanning electron microscope (SEM) respectively. The abrasive and corrosion resistance of the MAO-coating are examined by miniature wear instrument and electrochemical measurement. As adding micro-powder of alumina, potassium hydroxide, sodium pyrophosphate、sodium tungstate and nano-particles of silicon carbide in the electrolyte, the holes on MAO-coating become less and smaller, and thereby the properties of wear-resistance and corrosion resistance of the MAO-coating are enhanced.

The corrosion behavior of a carbon filled conducting organic coating for grounding Zn was investigated in a simulated solution of the soil of Shanbei area by means of EIS, SEM and open circuit potential measurement. The results showed that in the simulation solution, water and oxygen can migrate through the porous or defects in carbons net. The EIS data showed that the resistance of the coating decreased with the increasing immersion time. When water and oxygen reach the substrate surface, corrosion of Zn was enhanced as the anode part of the Zn/C galvanic corrosion system. The corrosion product was mainly composed of oxide of zinc.

The inhibitive action of FFFD-27SH inhibitor toward carbon steel corrosion in 3.5%NaCl solution was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results indicate that the addition of FFFD-27SH, which acts as an anodic type inhibitor, can effectively decrease the corrosion current densities of the carbon steel and increase the corrosion potential. EIS measurement results indicate that both of the charge transfer resistance and impedance increase greatly with the addition of FFFD-27SH and the double electric layer capacitance decreases significantly. The inhibition efficiency increases with the increase in inhibitor concentration, but changes little when its concentration is over 3%.

The durability of epoxy resin coating exposed in oxygen atmosphere at 110 ℃ for 5000 h has been studied by means of infrared spectroscopy (IR) and differential scanning calorimetry (DSC) to examine the evolution of chemical structure and the density of epoxy network for three kinds of epoxy coatings. The results show that the epoxy system with a stoichiometric ratio of 0.7 had a better resistance to thermal-oxidation, which might be resulted from the strong post-curing ability of the epoxy coating. The density of the 3 coatings after crosslinking treatment exhibited little change. Thermal aging was mainly derived from the reaction of the oxygen atoms with nitrogen atom on the cross-linked network nodes, while amide and carboxyl groups were the main oxidation products. Therewith the presence of acid groups might facilitate the fracture of molecular chains.

The failure of the fracture of a human master femur bone connection plate has been analyzed by means of optical emission spectrometer, Vickers hardness tester, optical microscope and scanning electron microscope (SEM). Experimental results and analyses demonstrate that the quality of the fractured material is qualified and meets the performance requirements. Some corrosion pits were found on the cracked substrate surface of the bone connection plate. A number of micro-cracks were nucleated in the pits, and their propagation directions were be confirmed on the SEM morphologies of the fractured surface. Some corrosion pits were also found in the substrate surface that was far away from the cracked surface. The authors suggest that pits aggravated the degree of stress concentration and then induced micro-cracks, at last resulted in fatigue fracture.

Failed fitting samples of a 500 kV electric power transmission line was investigated by means of mechanical property test, electrochemical test, as well as SEM and XRD characterization. The results show that sulfur is the critical factor of fittings corrosion. It forms soluble sulfate to consume zinc coatings faster. Furthermore, tensile stress and fretting corrosion also affect the fittings corrosion. The conclusions coincide fairly well with the service situations of fittings in terms of acid rain and corrosion in the relevant areas of Guangxi and Hunan province. Then anti-corrosion measures for fittings in industrial areas are proposed.

The silver conductive adhesives were prepared by silver powder and a kind of organic silicon resin as matrix, the later was a condensation product of silicon resin with dibutyltin dilaurate as catalyst. Then the failure process of the adhasive was studied in humid atmospheres. The adhesives before and after exposure in humid atmospheres were examined by means of SEM and EDS. Results indicated the failure of the adhesive was due to that silver powders within the adhesive reacted with H₂S, SO₂ and H₂O from the atmospheres, then generated compounds such as Ag₂S, Ag₂SO₃ and Ag₂O. In the meanwhile, the bulk resistivity of silver conductive adhesives was measured; the effect of exposure time and silver content on the electrical conductivity was also characterized. Results showed that the bulk resistivity of silver conductive adhesives increased with the increasing of exposure time, and decreased with the increasing of silver content.