The kinetics of zinc dissolution in aerated sodium sulphate solutions. A measurement of the corrosion rate by impedance techniques

Deslouis, C.; Duprat, M.; Tournillon, Chr.

doi:10.1016/0010-938x(89)90077-2

Cited by 73 publications

(34 citation statements)

References 12 publications

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“…Therefore, the diagram at LF is composed of a capacitive loop between two inductive loops. In the literature, only one model was proposed to describe the process of dissolution of pure zinc in Na 2 SO 4 [7] or in NaCl [8,9,18]. The model highlighted two processes in parallel with the presence of two adsorbed species (see reaction pathway on However, one has to consider that the increase of NaCl concentration from 0.1 to 1M brought about a shift of pH from 6 to 7.…”

Section: Effects Of Concentration and Of Phmentioning

confidence: 99%

On the corrosion resistance of porous electroplated zinc coatings in different corrosive media

2010

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The corrosion resistance of an electroplated (EP) Zn coating whose surface was chemically etched to produce surface defects (pores) is investigated in this work. Impedance and DC polarisation measururements were employed to study the behaviour of such coating in various corrosive media (NaCl, NaOH and rain water). Four different faradaic relaxation processes were clearly revealed in different NaCl concentrations (from 0.1M to 1M). In the most concentrated solutions at least three relaxation processes at low frequencies (LF) appeared and were related to zinc deposition and dissolution. At lower concentrations and depending on the pH, only one process was observed. The charge transfer resistance (R ct ) and the corrosion current (I corr ) were practically stable in the pH range 5 to 10. In deaerated NaCl 0.1M, the EIS diagrams showed two time-constants at very close frequencies. From the EIS diagrams the 2 porous nature of the coating was highlighted and showed that the dissolution mechanisms occurred at the base of the pores.

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Section: Effects Of Concentration and Of Phmentioning

confidence: 99%

On the corrosion resistance of porous electroplated zinc coatings in different corrosive media

2010

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“…Figure 3 shows a Nyquist representation of the time dependent electrochemical impedance, while Figure 4 illustrates the electrical equivalent circuits able of simulating the physicochemical processes taking place at the coated steel surface. It is important to emphasize that experimental impedance data obtained for A and B samples were analyzed on the basis of the electric equivalent circuit depicted in Figure 4(a)., while for the C samples was used the shown in Figure 4(b) [35]. In these figures, R sol represents the electrolyte resistance between the reference and working (coated steel) electrodes; the first time constant (R1Q1) -where R1 and (Q1  C1) are respectively the resistance to the ionic flux and the dielectric capacitance of the conversion layer -appears at the higher frequencies.…”

Section: Electrochemical Impedance Spectroscopymentioning

confidence: 99%

Anti-Corrosion Performance of Cr+6-Free Passivating Layers Applied on Electrogalvanized

Tomachuk¹,

Sarli²,

Elsner³

2010

MSA

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“…En soluciones con valores de pH entre 8,5 y 12, el zinc puede ser cubierto por una capa de hidróxido, la cual inhibe la disolución del zinc [13]. El comportamiento electroquímico del zinc depende de las especies disueltas, la concentración, el pH y la temperatura [14][15][16][17]. La presencia de varias especies químicas puede variar la solubilidad de los productos de la disolución del zinc formando complejos con los iones de zinc, aumentando la conductividad del electrolito, modificando la composición, al estructura y la compacidad de los productos de corrosión, formando una película salina insoluble sobre la superficie, proporcionando reactivos para la reacciones anódica y catódica, y cambiando la cinética de reacción a través de la adsorción catalítica o inhibitoria [2].…”

Section: Introductionunclassified

Análisis de la resistencia a la corrosión en lluvia ácida simulada de lasaleaciones Zn-Sn

2015

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RESUMENEl zinc y el estaño, junto con las aleaciones Zn-Sn, son empleados en la industria como recubrimientos del acero frente a la corrosión. Uno de sus usos más frecuentes es el galvanizado para exteriores, el cual es afectado por la corrosión debido a la lluvia ácida.El objetivo del trabajo es evaluar el comportamiento electroquímico que presentan las aleaciones Zn-Sn, con respecto a los metales puros, en una solución acuosa de lluvia ácida simulada compuesta por 31,85 mg/L H 2 SO 4 , 15,75 mg/L HNO 3 , 21,25 mg/L NaNO 3 , 46,20 mg/L (NH 4 ) 2 SO 4 , 31,95 mg/L Na 2 SO 4 , 84,85 mg/L NaCl, con un pH entre 3,5 y 4,0, a temperatura ambiente (25ºC). Para ello, se emplearon probetas de aleaciones con diferentes porcentajes en peso de estaño (6, 10 y 50), y de los metales puros, solidificadas horizontalmente.Se tomaron muestras de cada estructura de grano revelada y se las desbastaron con papeles de SiC, de granulometría entre #60 y #1200. Posteriormente, se realizaron medidas de polarización potenciodinámica en una celda electroquímica convencional de tres electrodos y ensayos de inmersión. Cada probeta se examinó mediante microscopia óptica, antes y después de realizar los ensayos.De las curvas potenciodinámicas se observó para los cortes transversales, que a medida que aumenta el contenido de estaño en la aleación, los potenciales tienden a valores más nobles. A partir de los ensayos de inmersión se denotó que la estructura columnar de zinc y las aleaciones presentan una mayor pérdida de masa que las demás estructuras. Además, el zinc y las aleaciones presentaron la velocidad máxima de corrosión al primer día de inmersión, para todas las estructuras de grano. En las micrografías se evidenció que el zinc presentó corrosión generalizada.Palabras clave: Aleaciones Zn-Sn, Lluvia ácida, Corrosión. ABSTRACTZinc and tin, together with Zn-Sn alloys are used in industrial operations and steel coatings against corrosion. One of its most common uses is the galvanizing process for outdoor structures, which is affected by corrosion caused by acid rain.The aim of the study is to evaluate the electrochemical behavior of Zn-Sn alloys with respect to pure metals, in an aqueous simulated acid rain solution consisting of 31.85 mg/L H 2 SO 4 , 15.75 mg/L HNO 3 , 21.25 mg /L NaNO 3 , 46.20 mg/L (NH 4 ) 2 SO 4 , 31.95 mg/L Na 2 SO 4 , 84.85 mg/L NaCl, at a pH between 3,5 and 4,0, at room temperature (25°C). Zn-Sn alloys samples were used with different percentages of tin (6 wt. % Sn, 10 wt. % Sn and 50 wt. % Sn), and pure metals samples. The samples were obtained by horizontal directional solidification.Samples of each of the revealed structures were taken and roughed with papers of SiC, of grain size between # 60 and # 1200. Subsequently, potentiodynamic polarization essays were performed in a conventional three electrode electrochemical cell and immersion tests. Each ones was examined by optical microscopy, before

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The kinetics of zinc dissolution in aerated sodium sulphate solutions. A measurement of the corrosion rate by impedance techniques

Cited by 73 publications

References 12 publications

On the corrosion resistance of porous electroplated zinc coatings in different corrosive media

On the corrosion resistance of porous electroplated zinc coatings in different corrosive media

Anti-Corrosion Performance of Cr+6-Free Passivating Layers Applied on Electrogalvanized

Análisis de la resistencia a la corrosión en lluvia ácida simulada de lasaleaciones Zn-Sn

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