PDF/Textbook Galvanic Mechanism Of Localized Corrosion For Mild Steel In Carbon Dioxide Environments Full Download

Galvanic Mechanism of Localized Corrosion for Mild Steel in Carbon Dioxide Environments

Author: Jiabin Han
Publisher:
ISBN:
Category : Carbon dioxide
Languages : en
Pages :

Book Description

Localized Corrosion Initiation of Steel in CO2 Environments

Author: Xin Gao
Publisher:
ISBN:
Category : Acetic acid
Languages : en
Pages : 191

Book Description
The objective of this dissertation research was to investigate initiation mechanisms for CO2 localized corrosion on mild steel, encompassing the effects of chloride, oxygen, and acetic acid. In CO2 corrosion, iron in steel will be oxidized to ferrous ions under deareated conditions. The ferrous and carbonate ions can combine to form FeCO3 and precipitate once exceeding the solubility limit. When the precipitation of FeCO3 occurs evenly on the steel surface it forms a compact and protective layer. This acts as a diffusion barrier hindering the mass transfer of electrochemical species and covers/blocks the surface making it unavailable for corrosion, which enhances the resistance of mild steel to further uniform CO2 corrosion. However, there are various scenarios where localized corrosion may occur. When the environment becomes more aggressive, the FeCO3 could be partially removed. This leads to localized regions of the bare steel surface that become exposed to the corrosive solution and, subsequently, localized corrosion could be initiated. To study CO2 localized corrosion, two-stage experiments were performed: (1) a uniform protective FeCO3 layer was first formed on a carbon steel with high initial FeCO3 saturation; (2) localized CO2 corrosion scenarios were then developed by adding additional salts (NaCl or NaClO4), oxygen or acetic acid to challenge the protective FeCO3 layer. The experiments were conducted in a two-liter glass cell with a three-electrode system, working electrode (X65 carbon steel), reference electrode (Ag/AgCl saturated electrode), and counter electrode (platinum). Electrochemical measurements (linear polarization resistance) were carried out to observe electrochemical behaviors and calculate the corrosion rates.

Mechanism of Localized Corrosion of Carbon Steel Pipe in Corrosion-inhibited, CO2-saturated Brine

Author: Bryon Daniels Winget
Publisher:
ISBN:
Category :
Languages : en
Pages : 178

Book Description

Oxides: Advances in Research and Application: 2011 Edition

Author:
Publisher: ScholarlyEditions
ISBN: 1464923892
Category : Science
Languages : en
Pages : 219

Book Description
Oxides: Advances in Research and Application: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Oxides. The editors have built Oxides: Advances in Research and Application: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Oxides in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Oxides: Advances in Research and Application: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Trends in Oil and Gas Corrosion Research and Technologies

Author: A. M. El-Sherik
Publisher: Woodhead Publishing
ISBN: 0081012195
Category : Science
Languages : en
Pages : 928

Book Description
Trends in Oil and Gas Corrosion Research and Technologies: Production and Transmission delivers the most up-to-date and highly multidisciplinary reference available to identify emerging developments, fundamental mechanisms and the technologies necessary in one unified source. Starting with a brief explanation on corrosion management that also addresses today's most challenging issues for oil and gas production and transmission operations, the book dives into the latest advances in microbiology-influenced corrosion and other corrosion threats, such as stress corrosion cracking and hydrogen damage just to name a few. In addition, it covers testing and monitoring techniques, such as molecular microbiology and online monitoring for surface and subsurface facilities, mitigation tools, including coatings, nano-packaged biocides, modeling and prediction, cathodic protection and new steels and non-metallics. Rounding out with an extensive glossary and list of abbreviations, the book equips upstream and midstream corrosion professionals in the oil and gas industry with the most advanced collection of topics and solutions to responsibly help solve today's oil and gas corrosion challenges. - Covers the latest in corrosion mitigation techniques, such as corrosion inhibitors, biocides, non-metallics, coatings, and modeling and prediction - Solves knowledge gaps with the most current technology and discoveries on specific corrosion mechanisms, highlighting where future research and industry efforts should be concentrated - Achieves practical and balanced understanding with a full spectrum of subjects presented from multiple academic and world-renowned contributors in the industry

Atmospheric Corrosion

Author: Christofer Leygraf
Publisher: John Wiley & Sons
ISBN: 1118762185
Category : Science
Languages : en
Pages : 509

Book Description
ATMOSPHERIC CORROSION Presents a comprehensive look at atmospheric corrosion, combining expertise in corrosion science and atmospheric chemistry Atmospheric corrosion has been a subject of engineering study, largely empirical, for nearly a century. Scientists came to the field rather later on and had considerable difficulty bringing their arsenal of tools to bear on the problem. Atmospheric corrosion was traditionally studied by specialists in corrosion having little knowledge of atmospheric chemistry, history, or prospects. Atmospheric Corrosion provides a combined approach bringing together experimental corrosion and atmospheric chemistry. The second edition expands on this approach by including environmental aspects of corrosion, atmospheric corrosion modeling, and international corrosion exposure programs. The combination of specialties provides a more comprehensive coverage of the topic. These scientific insights into the corrosion process and its amelioration are the focus of this book. Key topics include the following: Basic principles of atmospheric corrosion chemistry Corrosion mechanisms in controlled and uncontrolled environments Degradation of materials in architectural, transport, and structural applications; electronic devices; and cultural artifacts Protection of existing materials and choosing new ones that resist corrosion Prediction of how and where atmospheric corrosion may evolve in the future Complete with appendices discussing experimental techniques, computer models, and the degradation of specific metals, Atmospheric Corrosion, Second Edition continues to be an invaluable resource for corrosion scientists, corrosion engineers, conservators, environmental scientists, and anyone interested in the theory and application of this evolving field. The book concerns primarily the atmospheric corrosion of metals and is written at a level suitable for advanced undergraduates or beginning graduate students in any of the physical or engineering sciences.

Galvanic Interactions in Sweet and Sour Environments

Author: Angeire S. Huggins Gonzalez
Publisher:
ISBN:
Category : Carbon dioxide
Languages : en
Pages : 231

Book Description
Corrosion of carbon steel exposed to aqueous environments containing dissolved carbon dioxide (CO2) and hydrogen sulfide (H2S) is responsible for many failures of equipment and pipelines in the oil and gas industry. Corrosion product films, e.g., iron carbonate (FeCO3) and iron sulfide (FexSy), play a major role in enhancing localized corrosion after breakdown of these films by either mechanical or chemical means. This has been attributed to galvanic effects driven by the difference in open circuit potential (OCP) between steel covered by FeCO3 or FexSy and bare uncovered areas. Upon localized breakdown of the films, a galvanic current flows between the bare metal areas (anodes) and the areas covered with FeCO3 or FexSy (cathodes). Although many studies have evaluated these galvanic effects, there are still some questions remaining related to the cathodic nature of corrosion product films and their role in enhancing localized corrosion. The present study focused on the evaluation of galvanic interactions of iron (Fe) in CO2 and CO2/H2S environments. The corrosion rate and OCP were measured over time for samples under various conditions, corrosion products on those samples were characterized, and galvanic currents were measured between samples exposed to different conditions. The test conditions were selected to favor the formation of protective films. Fe and steel samples were immersed in 1% NaCl saturated with 100% CO2 or 0.1, 1, 10% H2S/balance CO2. The pH of the bulk solution was adjusted to values between 6 and 8, while the temperature was controlled between 20°C and 80°C. Corrosion product layers were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The galvanic interactions were measured using a modified split cell that allowed customization of different environments in each of the half cells, along with simultaneous monitoring of the galvanic current and driving force as indicated by the difference in OCPs. The results indicated that the pH of the bulk solutions plays a major role in the formation of protective FeCO3 scales. Fe exhibited a passive-like behavior when immersed in a solution at 80°C with pH adjusted to 8. The split cell experiments showed that after reaching a passive-like behavior, Fe was cathodic when coupled to samples immersed in a solution with lower pH, and the galvanic current was approximately 2.4 μA/cm2. The galvanic current decreased with increasing temperature and pH gradient between the half cells. The study of artificial couples between Fe electrodes in 1% NaCl solutions saturated with 0.1, 1 or 10% H2S/balance CO2 and with CO2 showed that the galvanic current increased with temperature and %H2S in the gas mixture. At 20°C and 0.1-1%H2S/balance CO2, the FexSy-covered electrodes were cathodic compared to Fe in CO2-saturated solution. At higher temperature and H2S/CO2 ratio, the FexSy covered samples were anodic. The reversal in polarity in the evaluation of temperature, pH and H2S/CO2 ratio suggested that the cathodic or anodic nature of FexSy films may be influenced by the local chemistry in the film/metal interface.