Menu
Search
Filters
Close
Menu

51318-11025-The Influence of Halide Ions on the Passivity Breakdown of Carbon Steel Based on the Point Defect Mo

Picture for The Influence of Halide Ions on the Passivity Breakdown of Carbon Steel Based on the Point Defect Model
Available for download

The influence of the size of aggressive anions on the passivity breakdown of UNS K02700 carbon steel exposed to saturated Ca(OH)2 solutions with the addition of different halides was investigated by using the potentiodynamic polarization (PDP) experiments.

 

Product Number: 51318-11025-SG
Author: Elmira Ghanbari / Danyil Kovalov / Alireza Saatchi / Bruno Kursten / Digby D. Macdonald
Publication Date: 2018
Industry: Science of Corrosion
$0.00
$20.00
$20.00

An important factor in determining the breakdown of the barrier layer of the passive film on carbon steel in halide-containing solutions is the anion size. In this study, the influence of the size of aggressive anions on the passivity breakdown of UNS K02700 grade carbon steel exposed to saturated Ca(OH)2 solutions with the addition of different halides was investigated by using the potentiodynamic polarization (PDP) experiments. The PDP results were interpreted by using a mechanistic description based on the Point Defect Model (PDM). The experimental results revealed a linear dependence of the critical breakdown potential (Ec) on the logarithm of the activity of the breakdown-inducing halide (F-, Cl-, Br-, and I-), as predicted by the PDM. Furthermore, the PDM successfully accounted for the order with which the halides induce passivity breakdown, F- < Cl- > Br- > I-, in terms of competitive Gibbs free energy of anion dehydration and expansion of surface oxygen vacancies, into which the halide must absorb as the initial event in the breakdown process.

Keyword: Passivity breakdown, Point Defect Model, Halide ion size

An important factor in determining the breakdown of the barrier layer of the passive film on carbon steel in halide-containing solutions is the anion size. In this study, the influence of the size of aggressive anions on the passivity breakdown of UNS K02700 grade carbon steel exposed to saturated Ca(OH)2 solutions with the addition of different halides was investigated by using the potentiodynamic polarization (PDP) experiments. The PDP results were interpreted by using a mechanistic description based on the Point Defect Model (PDM). The experimental results revealed a linear dependence of the critical breakdown potential (Ec) on the logarithm of the activity of the breakdown-inducing halide (F-, Cl-, Br-, and I-), as predicted by the PDM. Furthermore, the PDM successfully accounted for the order with which the halides induce passivity breakdown, F- < Cl- > Br- > I-, in terms of competitive Gibbs free energy of anion dehydration and expansion of surface oxygen vacancies, into which the halide must absorb as the initial event in the breakdown process.

Keyword: Passivity breakdown, Point Defect Model, Halide ion size

Product tags
Also Purchased
Picture for Evaluation of Corrosion Behavior of Steels for Direct Supercritical CO2 Power Cycle Applications
Available for download

51318-11017-Evaluation of Corrosion Behavior of Steels for Direct Supercritical CO2 Power Cycle Applications

Product Number: 51318-11017-SG
Author: Reyixiati Repukaiti / Ömer N. Doğan / Randal B. Thomas / Julie D. Tucker / Lucas Teeter / Margaret Ziomek-Moroz / Nicolas J. Huerta
Publication Date: 2018
$20.00

Autoclave tests were performed in CO₂, O₂, and H₂O at 8 MPa at 50°C and 245°C, (heat exchanger operating conditions). Results show significant corrosion in a pressure / temperature region where H₂O saturated with CO₂ condenses on the coupons.
Picture for Advancement in Cathodic Disbondment Test Standard- NACE TM0115
Available for download

51318-11018-Advancement in Cathodic Disbondment Test Standard- NACE TM0115

Product Number: 51318-11018-SG
Author: Benjamin T. A. Chang / Dennis Wong
Publication Date: 2018
$20.00

Special enhancements: (1) use the high temperature reference electrode - Ag/AgCl; (2) define the test temperature measurement procedure; (3) check the accuracy of the reference electrode; (4) develop an inexpensive anode isolation method.
Picture for Case Study: Solving the Puzzle of 10inch Duplex Stainless Steel Flowline Weld Failure
Available for download

51318-11022-Case Study: Solving the Puzzle of 10inch Duplex Stainless Steel Flowline Weld Failure

Product Number: 51318-11022-SG
Author: Mushaid Nauman, Mohammed Rashid
Publication Date: 2018
$20.00

This paper discusses the detailed inspection, testing, metallurgical analysis and supporting factors from which the most likely cause of pitting corrosion was revealed in the DSS flowline welds.

 
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