Download or read book Investigating the Mechanism of Transgranular Stress Corrosion Cracking in Near neutral Ph Environments on Buried Fuel Transmission Pipelines written by Stefanie Lynn Asher and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This research investigates the mechanism of transgranular stress corrosion cracking (TGSCC) on fuel transmission pipelines. This research proposes that in near-neutral pH environments, hydrogen can be generated by the dissociation of carbonic acid and the reaction of metal ions with bicarbonate solutions, significantly increasing the available hydrogen for diffusion into the pipeline steel. This research has shown that TGSCC of pipeline steels is possible in simple groundwater solutions containing bicarbonate ions and carbon dioxide. Microstructural characterization coupled with hydrogen permeation indicates that the level of strain in the microstructure has the most influence on hydrogen diffusivity. Hydrogen accumulation occurs preferentially in at high energy discontinuous interfaces such as inclusion interfaces. It was determined that a stress concentration is required to facilitate sufficient hydrogen accumulation in the pipeline steel in order to initiate TGSCC. It was discovered that these stress concentrations develop from inclusions falling out of the pipeline surface. Slow strain rate tests found that TGSCC occurred in a wide range of compositions and temperatures as long as near-neutral conditions were maintained. Microcracks ahead of the crack tip provide evidence of hydrogen in these cracking processes. Morphology of these microcracks indicates that cracks propagate by the coalescence of microcracks with the main crack tip. Further research findings, scientific impact, and potential future work are also discussed.

Download or read book Stress Corrosion Cracking of Pipelines written by Y. Frank Cheng and published by John Wiley & Sons. This book was released on 2013-02-19 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explains why pipeline stress corrosion cracking happens and how it can be prevented Pipelines sit at the heart of the global economy. When they are in good working order, they deliver fuel to meet the ever-growing demand for energy around the world. When they fail due to stress corrosion cracking, they can wreak environmental havoc. This book skillfully explains the fundamental science and engineering of pipeline stress corrosion cracking based on the latest research findings and actual case histories. The author explains how and why pipelines fall prey to stress corrosion cracking and then offers tested and proven strategies for preventing, detecting, and monitoring it in order to prevent pipeline failure. Stress Corrosion Cracking of Pipelines begins with a brief introduction and then explores general principals of stress corrosion cracking, including two detailed case studies of pipeline failure. Next, the author covers: Near-neutral pH stress corrosion cracking of pipelines High pH stress corrosion cracking of pipelines Stress corrosion cracking of pipelines in acidic soil environments Stress corrosion cracking at pipeline welds Stress corrosion cracking of high-strength pipeline steels The final chapter is dedicated to effective management and mitigation of pipeline stress corrosion cracking. Throughout the book, the author develops a number of theoretical models and concepts based on advanced microscopic electrochemical measurements to help readers better understand the occurrence of stress corrosion cracking. By examining all aspects of pipeline stress corrosion cracking—the causes, mechanisms, and management strategies—this book enables engineers to construct better pipelines and then maintain and monitor them to ensure safe, reliable energy supplies for the world.

Download or read book Developing a Predictive Model of Near neutral PH Stress Corrosion Cracking of Underground Pipelines written by Brett M. Conrad and published by . This book was released on 2014 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: Near neutral pH Stress Corrosion Cracking (NNpHSCC) on underground oil and gas pipelines is an issue facing industry today. Determining where NNpHSCC is likely to occur and grow is an important aspect to developing an Integrity Management Program. This work focused on developing a predictive model to capture the mechanisms involved with NNpHSCC growth utilizing actual field data. In order to better fit the field findings with the limited laboratory runs, different Hydrogen Enhancement Factors (HEF) were applied depending on the conditions of a given loading cycle. The predictive model generated results which demonstrated to distinct portions of NNpHSCC growth: a dissolution controlled phase and a mechanically activated phase. The output of the model was then compared to the field findings, with varied success. Further improvement and calibrations are required along with the gathering of additional field and laboratory data to fine-tune the field validation of the predictive model.

Download or read book Prediction of Conditions Leading to Stress Corrosion Cracking of Gas Transmission Lines written by N. Sridhar and published by . This book was released on 2000 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Corrosion, including stress corrosion cracking (SCC), constitutes about 12% of the failures of gas transmission lines. Two types of SCC have been observed: intergranular SCC (IGSCC) under alkaline conditions and transgranular SCC (TGSCC) under near-neutral conditions. The environmental and electrochemical conditions under which these types of SCC can be produced in the laboratory have been reasonably well established. However, a quantitative relationship between the laboratory environments in which SCC can be reproducibly observed and the chemistry of trapped water under disbonded coatings has not been established. The purpose of this paper is to review the state of knowledge of the environmental conditions leading to either type of SCC and relate this to the evolution of the actual environment under disbonded coating. The relationship between SCC and chemistry of trapped water is examined through the use of a comprehensive thermodynamic model. The temporal and spatial evolution of the trapped water chemistry is examined as a function of external conditions through the use of a reactive-transport model.

Download or read book Materials Science Research Trends written by Lawrence V. Olivante and published by Nova Publishers. This book was released on 2008 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials science includes those parts of chemistry and physics that deal with the properties of materials. It encompasses four classes of materials, the study of each of which may be considered a separate field: metals; ceramics; polymers and composites. Materials science is often referred to as materials science and engineering because it has many applications. Industrial applications of materials science include processing techniques (casting, rolling, welding, ion implantation, crystal growth, thin-film deposition, sintering, glassblowing, etc), analytical techniques (electron microscopy, x-ray diffraction, calorimetry, nuclear microscopy (HEFIB) etc.), materials design, and cost/benefit tradeoffs in industrial production of materials. This new book presents new leading-edge research in the field.

Download or read book Petroleum Abstracts written by and published by . This book was released on 1997 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stress Corrosion Cracking of Linepipe Steels in Near Neutral PH Environment written by W. Zheng and published by . This book was released on 2000 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stress corrosion cracking (SCC), a form of environment-assisted cracking, has caused 24 major pipeline failures in the Canadian oil and gas pipeline system. The role of stress in the SCC of linepipe steels in near-neutral pH environment, as in other SCC systems, is complex. In this paper, the effects of stress on the development of both axial cracking and circumferential cracking are reviewed. The long-term beneficial effect of compressive stress introduced by hydrostatic testing is also discussed.

Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2566 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Edit pour la cr ation des Officiers Greffiers au Parlement de Paris et aux Cours sup rieures et inf rieures written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stress Corrosion Cracking written by V S Raja and published by Elsevier. This book was released on 2011-09-22 with total page 817 pages. Available in PDF, EPUB and Kindle. Book excerpt: The problem of stress corrosion cracking (SCC), which causes sudden failure of metals and other materials subjected to stress in corrosive environment(s), has a significant impact on a number of sectors including the oil and gas industries and nuclear power production. Stress corrosion cracking reviews the fundamentals of the phenomenon as well as examining stress corrosion behaviour in specific materials and particular industries.The book is divided into four parts. Part one covers the mechanisms of SCC and hydrogen embrittlement, while the focus of part two is on methods of testing for SCC in metals. Chapters in part three each review the phenomenon with reference to a specific material, with a variety of metals, alloys and composites discussed, including steels, titanium alloys and polymer composites. In part four, the effect of SCC in various industries is examined, with chapters covering subjects such as aerospace engineering, nuclear reactors, utilities and pipelines.With its distinguished editors and international team of contributors, Stress corrosion cracking is an essential reference for engineers and designers working with metals, alloys and polymers, and will be an invaluable tool for any industries in which metallic components are exposed to tension, corrosive environments at ambient and high temperatures. - Examines the mechanisms of stress corrosion cracking (SCC) presenting recognising testing methods and materials resistant to SCC - Assesses the effect of SCC on particular metals featuring steel, stainless steel, nickel-based alloys, magnesium alloys, copper-based alloys and welds in steels - Reviews the monitoring and management of SCC and the affect of SCC in different industries such as petrochemical and aerospace

Download or read book Mechanistic Studies on Stress Corrosion Cracking of Pipeline Steels in Near neutral PH Environments written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Corrosion deformation Interactions CDI 96 written by Thierry Magnin and published by Woodhead Publishing Limited. This book was released on 1997 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published for: the European Federation of Corrosion.

Download or read book Effect of the Environment on Near neutral PH Stress Corrosion Cracking of X 52 Pipeline Steel written by Haishan Wang and published by . This book was released on 2009 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stress Corrosion Cracking of Pipelines in Contact with Near neutral PH Solutions written by Redvers N. Parkins and published by . This book was released on 1995 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stress corrosion Cracking written by Warren E. Berry and published by . This book was released on 1961 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Progresses in Fracture and Strength of Materials and Structures written by Yu Zhou and published by Trans Tech Publications Ltd. This book was released on 2007-09-10 with total page 3240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume is indexed by Thomson Reuters CPCI-S (WoS). The collection coveres all aspects of fracture and strength of materials and structure, particularly of advanced materials ranging from nanoscale to macroscale and modern structural systems ranging from large scale plants to micro- devices.

Download or read book Stress Corrosion Cracking of X65 Pipeline Steel in Fuel Grade Ethanol Environments written by Lindsey R. Goodman and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, the demand for alternatives to fossil fuels has risen dramatically, and ethanol fuel has become an important liquid fuel alternative globally. The most efficient mode of transportation of petroleum-based fuel is via pipelines, and due to the 300% increase in ethanol use in the U.S. in the past decade, a similar method of conveyance must be adopted for ethanol. Low-carbon, low-alloy pipeline steels like X52, X60, and X65 comprise the existing fuel transmission pipeline infrastructure. However, similar carbon steels, used in the ethanol processing and production industry, were found to exhibit stress corrosion cracking (SCC) in ethanol service. Prior work has shown that contaminants absorbed by the ethanol during distillation, processing or transport could be the possible determinants of SCC susceptibility; 200 proof ethanol alone was shown not to cause SCC in laboratory studies. To ensure the safety and integrity of the pipeline system, it was necessary to perform a mechanistic study of SCC of pipeline steel in fuel grade ethanol (FGE).\r : The objective of this work was to determine the environmental factors relating to SCC of X65 steel in fuel grade ethanol (FGE) environments. To accomplish this, a systematic study was done to test effects of FGE feedstock and common contaminants and constituents such as water, chloride, dissolved oxygen, and organic acids on SCC behavior of an X65 pipeline steel. Slow strain rate tests (SSRT) were employed to evaluate and compare specific constituents' effects on crack density, morphology, and severity of SCC of X65 in FGE. SCC did not occur in commercial FGE environments, regardless of the ethanol feedstock. In both FGE and simulated fuel grade ethanol (SFGE), SCC of carbon steel was found to occur at low water contents (below 5 vol%) when chloride was present above a specific threshold quantity. Cl- threshold for SCC varied from 10ppm in FGE to approximately 1 ppm in SFGE. SCC of carbon steel was inhibited when oxygen was removed from solution via N2 purge or pHe was increased by addition of NaOH. During SSRT, in-situƠ electrochemical measurements showed a significant role of film rupture in the SCC mechanism. Analysis of repassivation kinetics in mechanical scratch tests revealed a large initial anodic dissolution current spike in SCC-causing environments, followed by repassivation indicated by current transient decay. In the deaerated environments, repassivation did not occur, while in alkaline SFGE repassivation was significantly more rapid than in SCC-inducing SFGE. Composition and morphology of the passive film on X65 during static exposure tests was studied using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Results showed stability of an air-formed native oxide under static immersion in neutral (pHe = 5.4) SFGE, and dissolution of the film when pHe was decreased to 4.3. XPS spectra indicated changes in film composition at high pHe (near 13) and in environments lacking sufficient water. In light of all results, a film-rupture anodic-dissolution mechanism is proposed in which local plastic strains facilitates local breakdown of the air-formed oxide film, causing iron to dissolve anodically. During crack propagation anodic dissolution occurs at the crack tip while crack walls repassivate preserving crack geometry and local stress concentration at the tip. It is also proposed that SCC can be mitigated by use of alkaline inhibitors that speed repassivation and promotes formation of a more protective Fe(OH)3 film.