Because of their unique amorphous structure, metallic glasses (MGs) exhibit better corrosion resistance compared with traditional crystalline metals and alloys. Thus, MGs have broad application prospects as novel corrosion-resistant materials. The research progress of corrosion resistance of MGs was summarized. The influence factors, such as the alloy composition, microstructure, preparation method, corrosion environment, surface state, stress state etc. on the corrosion resistance of MGs were introduced. The routes to improve the corrosion resistance of MGs were proposed. Finally, the future development trends of corrosion resistance of MGs were discussed and prospected.

The research status on the matter of corrosion and protection related with sulfate-reducing bacteria (SRB) induced corrosion of steels in recent years was reviewed, and the formation process of anaerobic biofilm and its influence on steel corrosion were summarized. Based on this, the relevant mechanisms of SRB induced corrosion of metallic materials were introduced, including cathode depolarization mechanism, metabolite corrosion mechanism, Fe/FeS micro battery mechanism, etc. The role of extracellular polymer substances (EPS) resulted from SRB metabolism in the corrosion process of metallic materials was analyzed, and the synergistic effect of SRB with aerobic iron-oxidizing bacteria (IOB), typical corrosive anions (Cl^-/SO₄^2-), elastic stress and acid gas CO₂ was introduced in detail. Finally, the common anti-corrosion methods and the latest research progress in SRB corrosion research were also systematically summarized, so as to provide a reference for subsequent SRB corrosion and protection.

For chemical industry, the preparation technologies, the anti-oxidation mechanisms and the status of industrial applications of Si-Fe coatings are introduced. The research status of Si-Mo and Si-Zr coatings for the application of high temperature protection are overviewed particularly, simultaneously，the effect of various alloying elements on the anti-oxidation of silicide coatings and the relevant mechanisms are described. Compared to single-layer silicide coatings, bilayer or multi-layer composite coatings with excellent designability can meet simultaneously the requirements both of heat resistance of coatings and the adhesive strength between coatings and substrates, besides, which also can minimize defects such as the thermal expansion mismatch and elemental inter-diffusion between the coating and the substrate. Therefore, of which the performance advantages and structural design concept are illustrated. Lastly, the development trend of refractory metal silicide coatings is prospected so that to provide the proper reference for engineering application.

The influence of hydrostatic pressure on the corrosion behavior of X70 steel in simulated sea water was studied in the pressure range of 0~3 MPa by means of high temperature and high pressure reaction kettle, mass loss measurement, electrochemical means and slow strain tensile method, as well as XRD, SEM and EDS. The results showed that X70 steel suffered from localized corrosion and the main component of the corrosion product was FeOOH in the pressure range of 0~2 MPa. When the hydrostatic pressure was 3 MPa, the corrosion morphology turned to be general corrosion, and a small amount of Fe₃O₄ appeared in addition to FeOOH in the corrosion product. With the increase of hydrostatic pressure, the corrosion rate of X70 steel increased first and then decreased, and reached the maximum by 2 MPa. When the hydrostatic pressure was in the range of 0~2 MPa, the stress corrosion cracking (SCC) sensitivity of X70 steel increased with the increasing pressure, whereas, as the pressure increase up to 3 MPa, the SCC sensitivity decreased. The SCC sensitivity of X70 steel in the simulated sea water depended on the pitting degree on the steel surface, but not necessarily have a positive correlation to the hydrostatic pressure. With the increase of hydrostatic pressure, the anodic dissolution of X70 steel surface was promoted, and more hydrogen atoms were promoted to enter the steel. The SCC process of X70 steel in the simulated sea water could be ascribed to a mixed mechanism controlled by both anodic dissolution and hydrogen induced cracking.

The effect of chloride ion concentration, dissolved oxygen (DO) concentration and pH value of the water on the galvanic corrosion performance of the weld joint of 25Cr2Ni2MoV steel used for nuclear steam turbine rotor were investigated by means of potentiodynamic polarization measurements and electrochemical impedance spectroscopy. The results reveal that under different environmental variables selected, the welded joints of rotor steel exhibit a certain degree of galvanic corrosion effect, in which weld metal (WM) is preferentially corroded as the anode, and the corrosion resistance of WM and base metal (BM) decreases with the increasing chloride ion concentration, increasing dissolved oxygen content and decreasing pH value. In the environment of low chloride ion concentration (0.035 and 35 mg/L), the electrode process of WM and BM is controlled by ion diffusion, while in other environments, the electrode process is controlled by electrochemical activation. In addition, the increase of chloride ion concentration significantly enhances the galvanic corrosion effect of welded joints. The increase of dissolved oxygen concentration reduces the galvanic corrosion effect of welded joints, while the change of pH value under acidic conditions has no obvious effect on galvanic corrosion effects.

The long term oxidation behavior of T23 steel, one of the low alloy heat resistant steels was examined in high-temperature supercritical CO₂ at 650 ℃/25 MPa for 1000 h, so that, the oxidation kinetics of T23 steel was acquired. Meanwhile, the oxide scales formed on the steel were characterized by SEM, XRD and EDS. The results showed that the oxidation kinetics of T23 steel oxidized in high-temperature s-CO₂ at 650 ℃/25 MPa followed the cubic law during the entire test duration. Meanwhile, the time index was also obtained by data analysis process and proved to be 0.30. The oxide scales formed on all the samples exposed for different time duration had a typical double-layered structure. Namely，the outer layer was porous and composed of Fe₃O₄. The inner layer composed of Fe_3-xCr_xO₄ and was much denser than the outer layer. Also, the oxide scale formed on T23 steel in high-temperature s-CO₂ was more likely to peel off and the exfoliation-like corrosion could be found obviously on the surface of the corroded steel.

Thin films of layered double hydroxides (LDHs) such as ZnAl-LDHs and ZnAlCe-LDHs were grown in situ on the surface of AZ91D Mg-alloy via one-step hydrothermal method. The influence of Ce on the morphology, chemical composition and corrosion resistance of ZnAlCe-LDHs films on Mg-alloy was studied by means of X-ray diffractometer (XRD), scanning electron microscope (SEM), EDS and EIS. The results showed that Ce ion had little effect on the network-like morphology of LDHs nests, but increased the thickness of the films and the size of the nanosheets. In comparison with ZnAl-LDHs films, the free-corrosion potential of ZnAlCe-LDHs films shifted positively up to 0.05 V and the corrosion current density was decreased by 1~2 orders. In the impedance diagram, the arc radius was increased obviously, indicating that the addition of Ce ion can enhance the corrosion resistance of ZnAl-LDHs films on AZ91D Mg-alloy.

Galvanic corrosion should be considered when dissimilar metallic materials in contact with each other in a molten salt system of high ionic conductivity. Corrosion electrochemistry and immersion corrosion tests indicated that the difference of the corrosion potentials of different metal materials can be decreased or diminished by coupling Cr²⁺/Cr³⁺ into the 46.5%LiF-11.5%NaF-42.0%KF (in mole fraction) molten salt. Thus, the galvanic corrosion behavior between different metal materials can be effectively inhibited.

Numerical simulation could provide important information to optimize the regional cathodic protection system. However, the accuracy of numerical simulation is affected by several factors, especially by the boundary conditions, reflecting the coating condition, polarization characteristics of buried structures in the soil environment. The coating conditions of pipelines sometimes are quite different. It is difficult to determine the boundary conditions of buried pipelines accurately for in service stations. In this paper, the boundary conditions required for numerical simulation are acquired by inversion calculation, then based on the acquired boundary conditions, the optimal design for distribution of anode ground beds was carried out, therewith an optimized regional cathodic protection scheme was determined. Following the determined scheme, the construction of a regional cathodic protection system was realized, hence the calculation results were compared with the real field test results in the end. The margin of errors for the above two sets of results is under 10%, that verified reasonably the accuracy of the proposed method.

The corrosion inhibition performance of imidazoline (IM) in trichloroacetic acid (Cl₃CCOOH) solution on cold-rolled steel sheet was studied by means of mass loss method, potential polarization curve measurement and electrochemical impedance spectroscopy (EIS) as well as SEM and AFM. The hydrophilicity/hydrophobicity of the steel after immersion in the IM containing solution were assessed by contact angle measurement. While the adsorption mode of IM on the steel surface and the effect of protonation on the adsorption behavior of IE molecules are studied by quantum chemistry. The results show that IM can effectively slow down the corrosion of the cold-rolled steel in 0.10 mol/L Cl₃CCOOH solution, and the corrosion inhibition efficiency exceeds 95% in the solution with 500 mg/L IM at 20 ℃. The adsorption of Cl₃CCOOH on the steel surface is a mixed adsorption following the Langmuir adsorption isotherm. The Nyquist spectrum of the steel in 0.10 mol/L Cl₃CCOOH solution without and with addition of IM is all composed of capacitive reactance arc in the high frequency region and inductive arc in the low frequency region. However, after IM addition, the charge transfer resistance, inductor resistance and inductance value all increase significatly, meanwhile, the corrosion degree of the steel drops sharply. The contact angle test result showed that after IM addition, the hydrophobicity of the steel surface increased. Quantum chemical calculation results show that IM could easy be protonized to generate p-IM, therewith weakened its ability as electron donor whereas, strengthened that as electron acceptor.

The effect of temperature on the corrosion behavior of 14Cr12Ni3WMoV stainless steel for the final stage blade of steam turbine in 0.02 mol/L NaCl solution was studied by means of electrochemical techniques including open circuit potential measurement, potentiodynamic polarization measurement and electrochemical impedance spectroscopy, as well as laser scanning confocal microscopy and scanning electron microscopy coupled with energy dispersive spectroscopy. The results show that with the increasing temperature, both the corrosion tendency and corrosion rate of 14Cr12Ni3WMoV stainless steel increase. Meanwhile, its pitting sensitivity increases with weakened self-repairing ability of its passivation film, thus the corrosion resistance of the steel decreases. The corrosion pit develops faster in the radial direction，but its development in depth slows down with the increasing temperature. When pitting occurs, Fe, Cr, Ni, W, Mo and V in the steel selectively dissolve, demonstrating that Fe and Ni dissolve quickly, while Cr, W, Mo and V are enriched in the corrosion pit due to their slow dissolution, whereas the change of temperature has no obvious effect on the enrichment of Cr, W, Mo and V.

Three coatings of 45CT, NiCr/Cr₃C₂ and NiCrAlY were prepared on the surface of T91 steel by high velocity oxygen fuel spray. The hot corrosion behavior of the coated steel was examined in a simulated flue gas at 750 ℃ for the prepared samples enveloped with a layer of synthetic coal ash of 37.5%Na₂SO₄+37.5%K₂SO₄+15%Fe₂O₃+10%SiO₂. The sample was weighed at a certain interval to obtain the corrosion kinetic curve. The thickness changes of the coatings before and after 200 h corrosion were measured. The composition, structure and morphology of high temperature corrosion products were characterized by means of XRD, SEM and EDS. The results show that the bare T91 steel suffered from serious corrosion with corrosion products peeled off in large quantities. Mass gain in the early corrosion stage and then mass loss in the late corrosion stage was observed for the three coatings. After 200 h corrosion, the thinning amount of the three coatings 45CT, NiCr/Cr₃C₂ and NiCrAlY was about 25, 112.7 and 93.1 μm, respectively. The corrosion products remaining on the surface of T91 steel after corrosion were identified as mainly Fe₂O₃. The main corrosion products on the surface of 45CT coating was Cr₂O₃. However, the corrosion products of NiCr/Cr₃C₂ and NiCrAlY were Cr₂O₃ and NiCr₂O₄. Some coal ash particles were embedded in the corrosion products. For three coatings, corrosion media would diffuse through the coating to the coating/substrate interface during the test, which would lead to substrate corrosion. The substrate of beneath coatings of 45CT and NiCr/Cr₃C₂ suffered from serious corrosion, which led to cracks formation at the interface of coating and substrate. However, the substrate of beneath NiCrAlY coating showed slight corrosion, which may be ascribed to the low porosity and reactive element effect of rare earth of the coating.

The inhibition effect of brainea insignis extract (BIE) on the corrosion of Q235 steel in HCl solution was investigated by means of mass loss measurement, polarization curve measurement and electrochemical impedance spectroscopy. The results showed that BIE could effectively inhibit the carbon steel corrosion in HCl solution, as the BIE concentration was up to 560 mg·L^-1, the corrosion rate of Q235 steel decreased to 1.125 g·m^-2·h^-1, namely the corrosion inhibition efficiency reached 94.3%. Electrochemical analysis shows that the BIE extract suppressed mainly the cathodic corrosion reaction. With the increasing concentration of BIE extract, the charge transfer process on the metal surface was hindered increasingly, resulting in enhanced corrosion inhibition performance. The highest corrosion inhibition efficiencies calculated from the fitting of polarization curves and electrochemical impedance spectroscopy were 95.8% and 95.3%, respectively, which were in agreement with the result of mass loss measurement. The adsorption action of BIE molecules on the steel surface followed Langmuir, Temkin adsorption isotherms and the EI-Awady thermodynamic-kinetic model, and belonged to heterogeneous adsorption, whilst there should exist lateral interaction forces between the adsorbed organic molecules. Spectral analysis and surface morphology observations confirmed the existance of the adsorption action and corrosion inhibition of the extract molecules, respectively.

In view of the corrosion of 3A21 Al-alloy in glycol coolant, this paper studied the influence of trace amounts of Cl^- and Cu²⁺ ions on the corrosion behavior of 3A21 Al-alloy in ethylene glycol-water coolant at 50 ℃ by immersion experiments and surface analysis technology. The results indicated that Cl^- ions resulted in pitting corrosion of the alloy, and the pitting corrosion susceptibility increased with the increase of the concentration of Cl^-. Cu²⁺ ions could promote the breakdown of the passive film, and react with Al resulting in a deposition of metallic Cu on the Al-alloy surface, which in turn accelerated the corrosion of Al-alloy owing to the galvanic effect. 3A21 Al-alloy took place serious corrosion owing to the overlapping effect of the breakdown of the passive film and the galvanic effect in the case of co-existence of Cl^- and Cu²⁺.

The air cooler process with lean amine liquid was computationally simulated by means of Kent-Eisenberg (KE) model, while the variations of heat-stable salt, organic acid, CO₂ and other corrosive media during the cooling process in the temperature range of 83.40 ℃ to 41.96 ℃ were analyzed by means of soft wear Aspen plus. The results show that although the gas phase fraction of the first three rows of air cooler tube bundles is small, but within the gas phase, the molar fraction of heat-stable salt and CO₂ is 55% and 45%, respectively, in fact, which may be the key hazard source for corrosion of air cooler tube bundles. Following the analysis results of the flow characteristics in air-cooled tube bundles, it follows that the high-risk corrosion regions are located at the second row tube bundles of the air cooler, namely, the tube number No.9~12, 20, 21, 24, 27~40, which are consistent with the actual corrosion locations of the tube bundle during the operation of the air cooler with lean amine liquid in the factory.

The fatigue performance of the home-made nuts of 1Cr11Ni2W2MoV steel before and after shot peening was comparatively studied, while taking the commercial Shen made-nuts as reference, the two kinds of nuts are made corresponding to the same national specifications. The test results verify that the shot peening can improve the fatigue life of the nut. The stress lifting range of the home-made nut after the shot peening treatment is much higher than that of the blank ones. Under an applied larger static load ratio, the fatigue cycle times of the blank home-made nuts is lower. After shot peening, the home-made nut has a fatigue strength increment percent of 24.38% and a fatigue life profit fraction of 26.26%. Under the same shot peening condition, the fatigue resistance of the home-made nut after shot peening is significantly improved compared with the Shen made-nut of the same specification. When the applied maximum stress is 160 MPa, the cycle times of the home-made parts is increased by 87.8% compared with the Shen made-counterparts.

The corrosion behavior of the welded joint of 14Cr1MoR steel in 3.5% (mass fraction) NaCl solution was studied by means of mass loss measurement, polarization curve measurement, electrochemical impedance spectroscopy, and metallographic microscope. The results show that 14Cr1MoR steel is a kind of steel easy hardening by quenching and its welded joint presents a microstructure composed of coarse martensite, bainite, ferrite and a small amount of carbide, while they distribute randomly. Meanwhile, compared with the weld seam, the base metal of 14Cr1MoR steel has poor corrosion resistance, its corrosion morphology changes obviously in the short term, however by long-term soaking the formed corrosion products are loose, porous and easy to peel off, which exhibited poor protective effect on the base metal, so that the corrosion rate of the base metal is about 2 times higher than that of the weld seam.

A large number of organic corrosion inhibitors have been developed for the corrosion control of carbon steels, among others, the double Schiff base exhibits excellent prospect as a highly effective corrosion inhibitor，due to that multiple active sites can be introduced onto chains of its molecular. Based on years of experience in the synthesis of Schiff base corrosion inhibitors, this study adopted density functional theory (DFT) in quantum chemistry with the help of Gaussian09 software to computationally simulate the structural parameters of molecular for 6 kinds of 2-aminofluorene inhibitor, meanwhile, the active sites of interaction between the inhibitor and iron were analyzed, the corrosion inhibition mechanism was discussed, and finally a quantitative model of structural parameters of the molecular and the corrosion inhibition efficiency of the relevant inhibitors was constructed. This provides useful information for the synthesis of new corrosion inhibitors.

A model of graphene-enhanced DGEBA/3,3'-DDS cross-linked epoxy resin was established by Materials Studio software, and the diffusion process of water molecules in the anticorrosive coating of graphene-reinforced epoxy resin with different amount of graphene (0%，1.1%，2.3%，3.0%，4.2% and 5.8%，in mass fraction) was studied by molecular dynamics simulation method, aiming to search the theoretical guidance for the actual modification of epoxy resin coating. The results show that the water molecules are present within epoxy resin as two forms, namely the hydrogen bonded "bound water" and "free water" in internal micropores. The migration of water molecules in epoxy resin is mainly accomplished by the diffusion process of “free water” and the diffusion coefficient increased with the increase of temperature. The introduction of graphene makes the mean square displacement of water molecules more stable during the whole simulation process, which improved the barrier property of epoxy resin. In sum, the epoxy resin with addition of 4.2% graphene presented the best barrier performance.