Effectiveness of one-to-one phosphate to chloride molar ratio at different chloride and hydroxide concentrations for corrosion inhibition of carbon steel

Corrosion Inhibition Mechanism of Steel Reinforcements in Mortar Using Soluble Phosphates: A Critical Review

“…The concentration of phosphate species inside the pits was higher than the passive film zones without the pit. This indicates that phosphate ions could inhibit the corrosion process through a competitive adsorption mechanism with chloride ions where the chloride attack triggers the phosphate species to further adsorb at the pit locations on the metal surface [49]. In addition, the presence of phosphate ions stabilizes ferrihydrite, a poorly crystallized FeOOH, which may be a protective layer for steel in Cl − -contaminated concrete simulating solutions [8].…”

“…The surface analysis methods demonstrated that the inhibition mechanism of phosphate ions is attributed to the formation of a passive film with a duplex layer on the metal surface, including the inner layer of iron(hydro)oxides, formed by a solid-state mechanism and the outer layer of iron phosphate complexes mainly as FeHPO 4 , Fe 3 (PO 4 ) 2 and even Fe(PO 4 ), formed via a dissolution-precipitation mechanism [49].…”

Environmentally Friendly Antiagglomerants: A Promising Solution for Gas Hydrate Plugging and Corrosion Risk Management in Oil and Gas Pipelines

“…Figure demonstrates that as the concentration of the OADs increased, the Nyquist plot diameter became larger, which shows better inhibition performance of the inhibitors. The EIS data were well-fitted with the equivalent circuits (Figure S1), which includes solution resistance ( R s ), film resistance ( R f ), charge transfer resistance ( R ct ), and constant phase element (CPE) for the double layer and film. , A rough surface or nonhomogeneity in the system can cause capacitance of double layer ( C dl ) and film ( C f ) do not behave like an ideal capacitor, which should be replaced by the constant phase element (eq ). The C dl and C f values were derived by eqs and , respectively ,, Z CPE = Y − 1 × false( j · ω false) − n C dl = Y dl 1 / n dl true( R ct · R s R ct + R s true) ( 1 − n dl ) / n dl C f = ( g · Y normalf ) × false( 2 π · f δ false) n f − 1 g =...…”

The effect of riboflavin on the microbiologically influenced corrosion of pure iron by Shewanella oneidensis MR-1

“…With the increase of immersion time, the diameters of semicircles and the | Z| 0.01Hz values increased gradually for the coupons in the inoculated media, especially in the medium containing 20 ppm RF. Two time constants were observed in the phase angle plots of the coupons in the sterile medium, including one for the formation of a passive film and the other for the charge transfer process of iron corrosion [42]. The phase angle plots of the coupons in the inoculated media exhibited a broad peak in the medium to low frequency region, which could be associated with the formation of phosphate layer in the presence of bacteria and the charge transfer process on iron surface.…”

“…R f and R ct reflect the resistance of the surface film and the charge transfer resistance, respectively. For the sterile control, Q pass was used as the capacitance of the passive film [42]. A CPE is usually used instead of a pure capacitance to fit nonideal films on the surface.…”