Search
Filters

51318-11192-Investigation of FeCO3 and FeS Precipitation Kinetics by EQCM

In the present study, the precipitation kinetics of iron carbonate (FeCO3) and iron sulfide (FeS) were studied over a range of temperatures to gain a better understanding of their effect on corrosion resistance.

Product Number: 51318-11192-SG
Author: Zheng Ma / Yang Yang / Bruce Brown / Srdjan Nesic / Marc Singer
Publication Date: 2018
$0.00
$20.00
$20.00

Corrosion product layers play a key role in the corrosion processes by precipitating on the steel surface and can lead either to enhanced corrosion protection or, in some cases, to severe pitting, depending on the conditions. The kinetics of precipitation of corrosion product layers has a direct impact on the layers properties and their level of protectiveness. In the present study, the precipitation kinetics of iron carbonate (FeCO3) and iron sulfide (FeS) were studied over a range of temperatures to gain a better understanding of their effect on corrosion resistance. An Electrochemical Quartz Crystal Microbalance (EQCM) was used to investigate the FeCO3 precipitation kinetics in an aqueous CO2 environment, as well as the FeS precipitation kinetics in an aqueous H2S environment. In addition, different substrates were used to isolate specific aspects of the precipitation mechanisms: a cathodically polarized gold-coated quartz crystal, a cathodically polarized iron-coated quartz crystal, and a freely corroding iron-coated quartz crystal were used for FeCO3 precipitation; the two latter ones were used for FeS precipitation. The measured precipitation rates in both environments were repeatable and consistent across different substrates and over the range of temperatures tested. The FeCO3 precipitation rates exhibited a relatively strong dependency on system temperature and bulk saturation level of FeCO3. However, FeS precipitation kinetics appeared only weakly sensitive to the change of temperature. In addition, it is also postulated that the FeS saturation level at the substrate surface (rather than in the bulk), should be taken into consideration when the bulk saturation level of FeS is relatively low. The theoretical kinetic constant and the activation energy for both FeCO3 and FeS (based on bulk) were derived from the obtained EQCM results and compared with literature values.

Keywords: EQCM, iron carbonate, iron sulfide, precipitation kinetics

Corrosion product layers play a key role in the corrosion processes by precipitating on the steel surface and can lead either to enhanced corrosion protection or, in some cases, to severe pitting, depending on the conditions. The kinetics of precipitation of corrosion product layers has a direct impact on the layers properties and their level of protectiveness. In the present study, the precipitation kinetics of iron carbonate (FeCO3) and iron sulfide (FeS) were studied over a range of temperatures to gain a better understanding of their effect on corrosion resistance. An Electrochemical Quartz Crystal Microbalance (EQCM) was used to investigate the FeCO3 precipitation kinetics in an aqueous CO2 environment, as well as the FeS precipitation kinetics in an aqueous H2S environment. In addition, different substrates were used to isolate specific aspects of the precipitation mechanisms: a cathodically polarized gold-coated quartz crystal, a cathodically polarized iron-coated quartz crystal, and a freely corroding iron-coated quartz crystal were used for FeCO3 precipitation; the two latter ones were used for FeS precipitation. The measured precipitation rates in both environments were repeatable and consistent across different substrates and over the range of temperatures tested. The FeCO3 precipitation rates exhibited a relatively strong dependency on system temperature and bulk saturation level of FeCO3. However, FeS precipitation kinetics appeared only weakly sensitive to the change of temperature. In addition, it is also postulated that the FeS saturation level at the substrate surface (rather than in the bulk), should be taken into consideration when the bulk saturation level of FeS is relatively low. The theoretical kinetic constant and the activation energy for both FeCO3 and FeS (based on bulk) were derived from the obtained EQCM results and compared with literature values.

Keywords: EQCM, iron carbonate, iron sulfide, precipitation kinetics

Also Purchased
Picture for 96003 ELECTROCHEMICAL PROPERTIES OF IRON
Available for download

96003 ELECTROCHEMICAL PROPERTIES OF IRON DISSOLUTION IN THE PRESENCE OF CO2 - BASICS REVISITED

Product Number: 51300-96003-SG
ISBN: 96003 1996 CP
Author: Srdjan Nesic, Nicolas Thevenot, Jean-Louis Crolet, Dragutin M. Drazic
$20.00
Picture for 05295 Iron Carbonate Scale Formation and CO2
Available for download

05295 Iron Carbonate Scale Formation and CO2 Corrosion in the Presence of Acetic Acid

Product Number: 51300-05295-SG
ISBN: 05295 2005 CP
Author: Omkar Nafday and Srdjan Nesic, Ohio University
$20.00