Aluminum coatings on Mg alloy AZ31 were fabricated using the thermal spraying technique, and then sealed with silane.The surface morphology and chemical groups were discerned using scanning electron microscopy and exa...Aluminum coatings on Mg alloy AZ31 were fabricated using the thermal spraying technique, and then sealed with silane.The surface morphology and chemical groups were discerned using scanning electron microscopy and examined using Fourier transformation infrared spectroscopy, respectively.The salt fog tests and the potentiodynamic electrochemical technique were applied to evaluate the influence of silane on corrosion of the AZ31 alloy with aluminum coatings.The results showed that the corrosion resistance of the aluminum-coated AZ31 alloy was superior to that of the substrate.The aluminum coating sealed with various silane layers led to a further increase in the corrosion resistance of the alloy.Double silane layers were more corrosion-resistant than the single one.Also, it was no longer significant for more than two silane layers to improve the corrosion resistance.It implied that the optimum choice for silane treatment on the aluminum coatings was two layers.展开更多
This paper describes coating protection of production facilities of offshore oil fields based on the practice of development of Bohai Offshore Oil Field, with focus laid on the selection of coating systems, surface pr...This paper describes coating protection of production facilities of offshore oil fields based on the practice of development of Bohai Offshore Oil Field, with focus laid on the selection of coating systems, surface preparation, coating application, as well as coating inspection for four types of major production facilities.展开更多
The study focused on investigating the effectiveness of functional acrylic polymer (AP) in improving the ability of airfoamed sodium silicate-activated calcium aluminate/Class F fly ash cement (slurry density of ￡1.3...The study focused on investigating the effectiveness of functional acrylic polymer (AP) in improving the ability of airfoamed sodium silicate-activated calcium aluminate/Class F fly ash cement (slurry density of ￡1.3 g/cm3) to mitigate the corrosion of carbon steel (CS) after exposure to hydrothermal environment at 200?C or 300?C. Hydrothermally-initiated interactions between the AP and cement generated the formation of Ca-, Al-, or Na-complexed carboxylate derivatives that improved the AP’s hydrothermal stability. A porous microstructure comprising numerous defect-free, evenly distributed, discrete voids formed in the presence of this hydrothermally stable AP, resulting in the increase in compresive strength of cement. The foamed cement with advanced properties conferred by AP greatly protected the CS against brine-caused corrosion. Four major factors governed this protection by AP-incorporated foamed cements: 1) Reducing the extents of infiltration and transportation of corrosive electrolytes through the cement layer deposited on the underlying CS surface;2) Inhibiting the cathodic reactions at the corrosion site of CS;3) Extending the coverage of CS by the cement;and 4) Improving the adherence of the cement to CS surface.展开更多
基金supported by the Key Technologies Research & Development Program of Chongqing Science and Technology Commission (CSTC) (Nos. 2007AC4073 and 2009AB4008)the Natural Science Foundation of CSTC, China (No. 2008BB0063)
文摘Aluminum coatings on Mg alloy AZ31 were fabricated using the thermal spraying technique, and then sealed with silane.The surface morphology and chemical groups were discerned using scanning electron microscopy and examined using Fourier transformation infrared spectroscopy, respectively.The salt fog tests and the potentiodynamic electrochemical technique were applied to evaluate the influence of silane on corrosion of the AZ31 alloy with aluminum coatings.The results showed that the corrosion resistance of the aluminum-coated AZ31 alloy was superior to that of the substrate.The aluminum coating sealed with various silane layers led to a further increase in the corrosion resistance of the alloy.Double silane layers were more corrosion-resistant than the single one.Also, it was no longer significant for more than two silane layers to improve the corrosion resistance.It implied that the optimum choice for silane treatment on the aluminum coatings was two layers.
文摘This paper describes coating protection of production facilities of offshore oil fields based on the practice of development of Bohai Offshore Oil Field, with focus laid on the selection of coating systems, surface preparation, coating application, as well as coating inspection for four types of major production facilities.
文摘The study focused on investigating the effectiveness of functional acrylic polymer (AP) in improving the ability of airfoamed sodium silicate-activated calcium aluminate/Class F fly ash cement (slurry density of ￡1.3 g/cm3) to mitigate the corrosion of carbon steel (CS) after exposure to hydrothermal environment at 200?C or 300?C. Hydrothermally-initiated interactions between the AP and cement generated the formation of Ca-, Al-, or Na-complexed carboxylate derivatives that improved the AP’s hydrothermal stability. A porous microstructure comprising numerous defect-free, evenly distributed, discrete voids formed in the presence of this hydrothermally stable AP, resulting in the increase in compresive strength of cement. The foamed cement with advanced properties conferred by AP greatly protected the CS against brine-caused corrosion. Four major factors governed this protection by AP-incorporated foamed cements: 1) Reducing the extents of infiltration and transportation of corrosive electrolytes through the cement layer deposited on the underlying CS surface;2) Inhibiting the cathodic reactions at the corrosion site of CS;3) Extending the coverage of CS by the cement;and 4) Improving the adherence of the cement to CS surface.
