Menu
Search
Filters
Close
Menu

CP of Steel in Soil: Temporospatial pH and Oxygen Variation as a Function of Soil Porosity

Picture for CP of Steel in Soil: Temporospatial pH and Oxygen Variation as a Function of Soil Porosity
Available for download
Product Number: 51321-16313-SG
Author: Federico Martinelli/Ueli Angst
Publication Date: 2021
$0.00
$20.00
$20.00

This paper documents an investigation of pH variations in water saturated sandy soil with steel samples under impressed current cathodic protection (CP).The aim of this work was to evaluate the temporal and spatial variation in pH and oxygen under different protection current density and different soil porosity.Carbon steel samples were buried in quartz sand saturated with a simulated soil solution. The pH variation was determined by means of planar optical sensors and iridium oxides (IrOx) sensors. The oxygen variation was determined by means of fiber optical oxygen sensors. Different soil porosities were studied by dosing quartz sand with various granulometry.The increase of pH at the sample surface occurred within the first 10 hours from CP application independently from the soil porosity. The alkalinity produced from CP, and thus the near-field pH, was dependent on the cathodic current density. The pH gradient as a function of the distance from the steel surface was dependent on the soil porosity.The oxygen consumption rate at the steel surface was dependent on the cathodic current density. The oxygen concentration at the steel surface was reduced by at least 50% within 20 hours of CP application independently from the soil porosity.Thus, this work confirms that CP increases the pH and reduces the oxygen concentration at the working electrode, thereby strengthening the established view that corrosion protection can be achieved through generating conditions that facilitate passivation.

Keywords:Cathodic Protection, Corrosion control, Corrosion monitoring, Oxygen, pH, Sensors, Soil, Underground corroison

This paper documents an investigation of pH variations in water saturated sandy soil with steel samples under impressed current cathodic protection (CP).The aim of this work was to evaluate the temporal and spatial variation in pH and oxygen under different protection current density and different soil porosity.Carbon steel samples were buried in quartz sand saturated with a simulated soil solution. The pH variation was determined by means of planar optical sensors and iridium oxides (IrOx) sensors. The oxygen variation was determined by means of fiber optical oxygen sensors. Different soil porosities were studied by dosing quartz sand with various granulometry.The increase of pH at the sample surface occurred within the first 10 hours from CP application independently from the soil porosity. The alkalinity produced from CP, and thus the near-field pH, was dependent on the cathodic current density. The pH gradient as a function of the distance from the steel surface was dependent on the soil porosity.The oxygen consumption rate at the steel surface was dependent on the cathodic current density. The oxygen concentration at the steel surface was reduced by at least 50% within 20 hours of CP application independently from the soil porosity.Thus, this work confirms that CP increases the pH and reduces the oxygen concentration at the working electrode, thereby strengthening the established view that corrosion protection can be achieved through generating conditions that facilitate passivation.

Keywords:Cathodic Protection, Corrosion control, Corrosion monitoring, Oxygen, pH, Sensors, Soil, Underground corroison

Product tags
Also Purchased
Picture for 98667 TECHNIQUES FOR ASSESSMENT OF SOIL
Available for download

98667 TECHNIQUES FOR ASSESSMENT OF SOIL CORROSIVITY

Product Number: 51300-98667-SG
ISBN: 98667 1998 CP
Author: C. L. Durr, J. A. Beavers
$20.00
A Methodology, Database, and Maps For Seasonally-Adjusted Soil Resistivity
Available for download

A Methodology, Database, And Maps For Seasonally-Adjusted Soil Resistivity

Product Number: 51322-18216-SG
Author: Thomas Hayden, Alfonso Rojas Garcia, Steve Peaslee, Joseph Mazzella, Paul Murray, Robert R. Dobos
Publication Date: 2022
$20.00

The electrical conductivity of the electrolyte is one of the key parameters in the electromechanics of corrosion. Highly conductive electrolytes will permit more current and increase corrosion rates. Conversely, resistive electrolytes will enable less current to flow until the necessary conditions for corrosion are no longer satisfied or slowed.
Picture for Comparison of Sampling Analysis Findings and RBI Assessment in Corrosion Forecasting
Available for download

Comparison of Sampling Analysis Findings and RBI Assessment in Corrosion Forecasting

Product Number: 51321-16376-SG
Author: Yousef Khuraibut/ Saleh Al-Sulaiman/ Arnab Gupta/ Mithun Mitra/Hasan Bu Taleb
Publication Date: 2021
$20.00
Categories
Industry
Recently viewed
Popular tags
View all

Association for Materials Protection and Performance

© AMPP All Rights Reserved.
Membership Terms of Content Use
Contact Customer Support