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  • High-pressure CO2 pretreatment as a method for stainless steel passivation [Elektronski vir]
    Slemnik, Mojca ; Pečar, Darja
    Purpose - The purpose of this paper is to present a study of corrosion properties of the highly corrosion-resistant stainless steel Prokron 11Nb, which is suitable for use in high-temperature and ... high-pressure systems. Design/methodology/approach - Prokron 11Nb was immersed in 0.1M H2SO4 that hadbeen previously sparged with CO2 and was exposed to high pressures within the range of 1-300 bar at a constant temperature of 25 C. Treated surfaces were scanned with an electronic microscope (scanning electron microscope) equipped with energy spectrum distribution (energy dispersive spectroscopy) to analyze the morphologies and compositions of surface deposits. Corrosion properties were measured using the potentiodynamic method and electrochemical impedance spectroscopy. Findings - The corrosion rate decreased with increasing CO2 pressure, which accelerated surface passivity, but only up to apressure of 200 bar. Higher pressures (300 bar) increased the corrosion rate.The trends in corrosion rate with CO2 pressure agree with the stability of a protective layer where iron carbonate is present. Originality/value - A high-pressure CO2 treatment at low temperature is found to be a useful method for improving the passivity of stainless steel. Iron carbonate, which is the result of CO2 corrosion, forms a stable protective layer on the steel surface and this lowers the corrosion rate.
    Source: Anti-corrosion methods and materials. - ISSN 0003-5599 (Vol. 57, iss. 6, 2010, str. 290-296)
    Type of material - e-article
    Publish date - 2010
    Language - english
    COBISS.SI-ID - 14616342
    DOI

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