Download or read book Influence of Alloying Elements Testing Solution and Surface Roughness on Corrosion Behaviour of Stainless Steel Reinforcing Bars written by Ibrahim Ogunsanya and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The province of Ontario has moved from applying rock salt crystals, predominantly impure sodium chloride, to locally available anti-icing brine solutions with chloride amounts as high as 21%. At the same time, the specified design service life of highway structures has increased from 50 years to 75 years. The exposure to aggressive chloride brines has increased the need for more corrosion resistant reinforcing bar (rebar) than the traditional carbon steel rebar. However, the high cost of many stainless steel rebar alloys made them a last resort when concrete reinforcement options are considered. A major factor for their high cost is the price of their major alloying elements. Therefore, the contributions of these elements towards passive film properties, pitting corrosion resistance, critical chloride threshold (CCRIT) values and overall corrosion performance in the presence of deleterious species in concrete, such as chlorides, must be ascertained. This research aimed to provide a critical evaluation of the various parameters affecting long term corrosion performance of different grades of stainless steel rebar in concrete exposed to anti-icing brines. The first step to achieving this was to determine the variation in pore solution compositions of different concrete mixes so that bars can be tested in a similar environment. To do this, cement pastes of varying admixed chloride content, cementitious materials and water-to-cementitious ratio (w/cm) were cast and their pore solutions were analyzed for ionic composition and pH. The results revealed increasing dissolution of sulphate ions with increasing admixed chloride ions in the pore solution. These actual solutions were used in subsequent assessment procedures involving electrochemical techniques such as Mott-Schottky analysis, potentiostatic linear and non-linear polarization resistance and cyclic potentiodynamic polarization techniques. The goal was to determine the passive film properties, pitting characteristics, critical chloride threshold (CCRIT) and relative corrosion performance of carbon steel and five grades stainless steel rebar. Results showed the addition of sulphates to testing solutions suppressed the damage from chloride ions on steel passive films, by forming iron and nickel sulphides in passive films that provided additional protection. Results also showed that testing in lower pH solution, as done by many researchers, is conservative and underestimates corrosion resistance. The influence of the expensive stainless steel alloying elements (Cr, Ni, Mo, Mn) on the corrosion parameters listed above were then investigated. Chromium significantly improved these properties by decreasing passive film defects and increasing CCRIT values of the rebar. Molybdenum did not improve the corrosion resistance in the austenitic alloys but was beneficial in duplex alloys by concentrating in the ferritic component. Nickel was found to improve the outer layer of passive films properties by forming an Fe-Ni spinel, while manganese improved the inner passive layer. It is necessary for these observations in corrosion behaviour of rebar to be consistent. Consequently, other factors potentially leading to variations in corrosion performance of stainless steel rebar alloys were examined. These included the influence of variability in composition, microstructure and surface roughness between batches of stainless steel alloys from different manufacturers, and results showed surface roughness to be the major and overwhelming factor in corrosion resistance. The most important observation has been that, for the particular concrete mixture used in this research, the critical chloride threshold concentration, found by extrapolation of the experimental data, was greater than the solubility limit of chlorides in cement pores. This implies that chloride induced corrosion of the stainless alloys would not be possible in this concrete in the absence of cracks or major flaws.

Download or read book Effects of Surface Condition on the Corrosion Performance of Stainless Steel Rebar written by Bradley P. Bergsma and published by . This book was released on 2009 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: Corrosion of carbon (black) steel reinforcing bars (rebar) is the major cause of damage and deterioration of reinforced concrete structures in maritime regions and in climates where de-icing salts are used. The cause of the corrosion is diffusion of chloride ions to the steel surface through the concrete in which it is placed. The bars are naturally passivated by the high pH of concrete interstitial pore fluid, and will not corrode in chloride-free concrete. Chloride ions break down the passive film, allowing dissolution of the steel. Corrosion of reinforcing steel drastically reduces the service lives of concrete structures. Where chlorides can not be avoided, stainless steel is becoming increasingly popular as an alternative reinforcing material. Stainless steel is able to withstand greater concentrations of chlorides, extending the service lives of structure in which they are placed. Due to high initial cost, stainless steel is often avoided in the design of new structures. In order to reduce the cost of stainless rebar, it has been proposed that the standard process of abrasive blasting and pickling of the steels not be performed, as these steps are mainly used to restore a bright and shiny surface, a quality not required for steels embedded in concrete. AISI 304LN, AISI 316LN and 2205 duplex stainless steels were tested with pickled surfaces as well as with mill-scale intact (as-rolled) in order to determine the affect of pickling vs. not pickling on the corrosion behaviour of the steels. Steels were tested in solutions simulating concrete interstitial pore fluid containing from 0 to 16% Cl- by mass of solution, simulating cement paste with 0 to 7.5% Cl- by mass of cement, which is near the solubility limit of Cl- in pore fluid. Steels were also tested in thin mortar shells, with Cl- ions being rapidly diffused to the surface due to an applied potential gradient. The microcell corrosion performance of the as-rolled steels was slightly worse than that of pickled steels; however, the corrosion rates of the as-rolled steels at 16% Cl- in pore fluid are near 3 [mu]m/year, while black steel is normally observed to be actively corroding at 10 [mu]m/year in cement containing as low as 0.1% Cl- by mass of cement, or 0.2% Cl- by mass of solution. No significant difference was observed between different grades of stainless steel in either the as-rolled or pickled conditions. As-rolled stainless steels exhibited poor pitting resistance when an anodic potential is applied, but the corrosion occurs at potentials much higher than experienced in service and at Cl- concentrations far greater than that needed to initiate corrosion on black steel; the time required to reach these higher Cl- levels would allow for maintenance free service long enough to justify the cost of as-rolled stainless steel over black steel. The Canadian Highway Bridge Design Code, CSA S6-06, specifies that reinforced concrete bridges should meet a service life of 75 years. It is concluded that, given the time required for concentrated chlorides to accumulate at the steel, the stainless steel rebar in the as-rolled condition would allow reinforced concrete structures to reach the specified service life, as long as care is taken to avoid contamination of the steel/surface by black steel from handling, or by secondary phases within the steel, Cr23C6 and MnS in particular.

Download or read book Study on the Perspective of Mechanical Properties and Corrosion Behaviour of Stainless Steel Plain and TMT Rebars written by Swarup Kumar Ghosh and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the present research, the effects of various alloying elements and microstructural constituents on the mechanical properties and corrosion behaviour have been studied for four different rebars. The microstructures of stainless steel and plain rebar primarily reveal equiaxed ferrite grains and ferrite-pearlite microstructures, respectively, with no evidence of transition zone, whereas tempered martensite at the outer rim, followed by a narrow bainitic transition zone with an internal core of ferrite-pearlite, has been observed for the thermomechanically treated (TMT) rebars. The hardness profiles obtained from this study display maximum hardness at the periphery, which decreases gradually towards the centre, thereby providing the classical U-shaped hardness profile for TMT rebars. The tensile test results confirm that stainless steel rebar exhibits the highest combination of strength (,âà755¬†MPa) and ductility (,âà27%). It has been witnessed that in Tafel plots, the corrosion rate increases for all the experimental rebars in 1% HCl solution, which is well expected because the acid solutions generally possess a higher corrosive environment than seawater (3.5% NaCl) due to their acidic nature and lower pH values. However, all the experimental results obtained from Tafel and Nyquist plots correlate well for both 1% HCl and 3.5% NaCl solutions.

Download or read book Metals Abstracts written by and published by . This book was released on 1995 with total page 1602 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Corrosion Protection of Reinforcing Steels written by fib Fédération internationale du béton and published by fib Fédération internationale du béton. This book was released on 2009-01-01 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: It has long been recognised that corrosion of steel is extremely costly and affects many industry sectors, including concrete construction. The cost of corrosion of steel reinforcement within concrete is estimated at many billions of dollars worldwide. The corrosion of steel reinforcement represents a deterioration of the steel which in turn detrimentally affects its performance and therefore that of the concrete element within which it has been cast. A great amount of work has been undertaken over the years concerning the prevention of corrosion of steel, including the application of coatings, which has included the study of the process of corrosion itself, the properties of reinforcing steels and their resistance to corrosion as well as the design of structures and the construction process. The objective of fib Bulletin 49 is to provide readers with an appreciation of the principles of corrosion of reinforcing steel embedded in concrete and to describe the behaviour of particular steels and their coatings as used to combat the effects of such corrosion. These include galvanised reinforcement, epoxy coated reinforcement, and stainless reinforcing steel. It also provides information on the relative costs of the materials and products which it covers. It does not deal with structure design or the process of construction or with the post-construction phase of structure management including repair. It is hoped that it will nevertheless increase the understanding of readers in the process of corrosion of reinforcing steels and the ability of key materials and processes to reduce its harmful effects.

Download or read book Atmospheric Corrosion written by Christofer Leygraf and published by John Wiley & Sons. This book was released on 2016-06-07 with total page 401 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book The Adaption of a Rapid Screening Test to Rank the Corrosion Behaviour of Stainless Steel Reinforcing Bars in Concrete written by Peter Gordon Houston Loudfoot and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The costs associated with aging reinforced concrete infrastructure in Ontario continue to rise as highway infrastructure, such as bridges, continuously deteriorate. The use of de-icing salts on these bridges in the winter often leads to the corrosion of the reinforcing steel, cracking the concrete and reducing the service life of the structure. To meet a minimum required service life of 75 years for bridge infrastructure, the Ministry of Transportation of Ontario uses stainless steel grades UNS S31653 (316LN) and UNS S31803 (2205) for corrosion resistance [1], [2]. However, with the wide variety of existing stainless steel grades and the continuous development of new grades, the selection of the most appropriate grade of stainless steel for current projects is limited by the time necessary to determine their corrosion resistance under realistic conditions. An experimental project was undertaken to determine, through a rapid screening test, if less costly grades of stainless steel would be competitive with 2205 or 316LN in their corrosion resistance. The relative corrosion resistance of three grades of stainless steel were compared: UNS S24100 (XM-28) and S32304 (2304) with S31803 (2205) as the “control”. The main objectives for this project were as follows: 1) to experimentally assess and evaluate the parameters of the Rapid Screening Test such that recommended parameters can be used to compare the relative corrosion resistance of new and existing grades of stainless steel, and 2) to assess the impact of the parameters on the probability of corrosion for each tested stainless steel grade using statistical analyses. The experimental procedure involved casting stainless steel specimens into concrete with admixed chloride concentrations of 4, 6, or 7.5% by mass of cementitious materials, measuring the open circuit potentials (Ecorr) of the specimens from 24 hours to 48 after casting, and immediately applying an anodic polarization potential of +100, +200, +300, or +400 mV to the specimens for 96 hours after the Ecorr monitoring period. During the applied polarization potential period, corrosion current density (icorr) values were monitored. Corrosion initiation was considered to have occurred if the icorr of a specimen surpassed the proposed pass/fail limit of 0.025 A/m2 for more than 2 hours. All specimens were autopsied at the end of the test and visually examined for any signs of corrosion. The results of the electrochemical testing and the observations made during and after autopsying the bars were found to differ. The detection of corrosion initiation in the electrochemical testing was then changed to reflect the results of the autopsied bars. If any bar had an increase in icorr by at least one order of magnitude, it is considered to have corroded. Logistic regression models were created to model the probability of corrosion in each of the tested grades of stainless steel based on the electrochemical testing and autopsy results. It was determined that increasing the admixed chloride concentration of the concrete has a far more significant impact on the corrosion initiation of the bars than the applied polarization potential. Theoretical critical chloride thresholds of the XM-28, 2304, and 2205 bars directly exposed to admixed chlorides in concrete were estimated to be 7.1%, 7.1%, and 9.4% by mass of cementitious materials, respectively. However, based on the limited pitting corrosion damage observed in the photomicrographs, it is believed that 2304 has a higher chloride threshold than XM-28. The threshold values of the 2304 and 2205 specimens may not be accurately estimated due to the imbalanced number of corroded versus non-corroded specimens for each of these grades. Based on the experimental and analytical results, 7.5% admixed chlorides by mass of cementitious and an applied polarization potential of +300 mV are the recommended parameters for the Rapid Screening Test. The proposed relative ranking of stainless steel specimens is based on the number of corroded specimens, the order of magnitude of the corrosion rates experienced by the specimens, and the severity of the pitting corrosion observed on the specimens. The ranking of the relative corrosion performance of the stainless steel grades tested in the Rapid Screening Test is as follows, in order of the most to least resistant: 2205, 2304, and XM-28. Based on the results of this test, it is recommended that 2304 would be a suitable alternative to 2205 as corrosion resistant reinforcing bars in concrete highway structures. It should be noted that chloride concentrations in excess of 5% by mass of cementitious material in concrete highway structures have not been reported in the available literature to date.

Download or read book Steels Metallurgy and Applications written by David Llewellyn and published by Elsevier. This book was released on 1998-02-24 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: STEELS: Metallurgy and Applications provides a metallurgical understanding of commercial steel grades and the design, manufacturing and service requirements that govern their application. The properties of different steels are described, detailing the effect of composition, processing and heat treatment. Where appropriate an introduction is given to standard specifications and design codes provided on component manufacture and property requirements for successful service performance. The book deals with steel products in some depth, in four chapters covering wide strip, structural steels, engineering and stainless steel grades. At the begining of each chapter an overview is given which details important features of the grades and a historical perspective of their development. Also featured are up to date information on steel prices and specifications. David Llewellyn has over thirty years experience in the steel industry and is currently lecturing in the Materials Engineering Department at University College Swansea. '..the book unfolds into an easily readable and a valuable source of highly relevant and contemporary information on steels' - METALS AND MATERIALS '.. a high quality product from all points of view' - INSTITUTE OF METALS AND MATERIALS AUSTRALASIA features up to date information on steel prices and specifications.

Download or read book The Effect of Surface and Loading Conditions on the Corrosion Performance of Stainless Steel Rebar written by Kyle A. Anders and published by . This book was released on 2009 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deterioration of reinforced concrete structures due primarily to chloride induced corrosion of plain carbon-steel reinforcement is a widespread problem, particularly in areas close to marine environments and where de-icing salts are used to keep roadways clear of ice. Replacing plain carbon-steel rebar with highly corrosion resistant stainless steel rebar has been shown to greatly increase the lifespan of concrete structures in harsh environments, and yields favourable life-cycle costs despite high initial costs. In attempt to lower stainless steel rebar's initial cost of processing, this research compared its corrosion resistance in the pickled (mill scale removed) and as-rolled (mill scale intact) surface conditions. Rebar was embedded in highly-chloride contaminated concrete, and corrosion performance between the two surface types was compared in order to determine if conventional pickling of stainless steel rebar is necessary. A second part of this research addressed possible concern of reduced corrosion resistance of pickled stainless steel rebar in concrete exposed to chlorides when subjected to dynamic loading due to micro-motion at the concrete/crack interface. It was concluded that as-rolled stainless steel rebar in aggressive environments would provide sufficient corrosion resistance for the 75 year lifespan currently specified by the Canadian Bridge Code (CAN/CSA-S6-06, 2006), however it is recommended that monitoring of these specimens be continued to ensure high corrosion rates and/or concrete cracking do not develop. As well, investigation into the effects crevice corrosion cells found in typical concrete structures could have on as-rolled stainless steel rebar's corrosion resistance should be undertaken. With regard to loading conditions, no significant evidence was found suggesting that pickled stainless steel rebar has reduced corrosion resistance when loaded dynamically versus statically. Therefore pickled stainless steel rebar is recommended for use in dynamically loaded concrete structures if others factors permit. However, the higher electrochemical noise measured during cyclic loading suggests that corrosion behaviour could be influenced largely by frequency of loading, and so further study should be undertaken for applications involving more extreme cyclic loading conditions than those used in this experiment.

Download or read book Metals Abstracts Index written by and published by . This book was released on 1995 with total page 1390 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Corrosion Effect of Stray Currents and the Techniques for Evaluating Corrosion of Rebars in Concrete written by Victor Chaker and published by ASTM International. This book was released on 1986 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advances in Manufacturing Engineering and Materials II written by Sergej Hloch and published by Springer Nature. This book was released on 2021-03-16 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reports on cutting-edge research and technologies in the field of advanced manufacturing and materials, with a special emphasis on unconventional machining process, rapid prototyping and biomaterials. It gathers contributions to the International Conference on Manufacturing Engineering and Materials (ICMEM 2020), which was originally planned in June 2020, but will actually take place in 2021, in Nový Smokovec, Slovakia, because of the Covid-19 pandemic. Despite the challenging times, submitted contributions were peer-reviewed, and upon a careful revision, included in this book, which covers advances that are expected to increase the industry’s competitiveness with regard to sustainable development and preservation of the environment and natural resources. Condition monitoring, industrial automation, and diverse fabrication processes such as welding, casting and molding, as well as tribology and bioengineering, are just a few of the topics discussed in the book’s wealth of authoritative contributions. A special emphasis is given to problems connected to climate change and solution manufacturer and engineers may adopt and develop to prevent and cope with them.

Download or read book Corrosion Testing for Metal Finishing written by V. E. Carter and published by Elsevier. This book was released on 2013-10-22 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: Corrosion Testing for Metal Finishing provides metal finishers with a range of test methods as well as guidance in the choice of method for a particular finish. There is a wide range of corrosion test methods available, the majority being the subject of Standard Specifications or being brought to Standards status. With many product Standards there is a choice of test methods available to met the Standard requirements. It is hoped that the relevant choice may be obtained more easily as a result of the information published in this book. The book outlines the apparatus and procedure for each test method and discusses its applicability to different metals and finishes. Indications are given of the nature and extent of the corrosion which develops in the test. Reference is also made to the relevant Standards for each test method. The book begins with a discussion of the basic requirements for corrosion testing of finished metal products. Subsequent chapters are devoted to testing procedures such as humidity tests, salt fog tests, industrial atmosphere test, porosity test, and anti-perspiration tests.

Download or read book GB T 42661 2023 Translated English of Chinese Standard GB T 42661 2023 GBT42661 2023 written by https://www.chinesestandard.net and published by https://www.chinesestandard.net. This book was released on 2024-01-21 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document specifies the principle, test solutions, specimens, test procedures and test report of the test method for determining susceptibility to stress corrosion of steel reinforcement in simulated marine environment. This document is applicable to the test of susceptibility to stress corrosion of steel reinforcement in simulated marine environment, such as: atmospheric areas, splash areas, tidal range areas (water-level change areas) and seawater immersion areas, etc., under concrete pore fluid conditions, using constant-load uniaxially loaded tension and slow strain rate methods.

Download or read book Corrosion of Steel in Concrete Structures written by Amir Poursaee and published by Woodhead Publishing. This book was released on 2023-02-20 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Essential reading for researchers, practitioners, and engineers, this book covers not only all the important aspects in the field of corrosion of steel reinforced concrete but also discusses new topics and future trends. Theoretical concepts of corrosion of steel in concrete structures, the variety of reinforcing materials and concrete, including stainless steel and galvanized steel, measurements and evaluations, such as electrochemical techniques and acoustic emission, protection and maintenance methods, and modelling, latest developments, and future trends in the field are discussed. Comprehensive coverage of the corrosion of steel bars in concrete, investigating the range of reinforcing materials, and types of concrete Introduces the latest measuring methods, data collection, and advanced modeling techniques Second edition covers a range of new, emerging topics such as the concept of chloride threshold value, concrete permeability and chloride diffusion, the role of steel microstructure, and innovations in corrosion detection devices

Download or read book Corrosion written by S. Syngellakis and published by WIT Press. This book was released on 2017-05-23 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: Corrosion is a degrading material process frequently encountered in engineering structures and components, which may lead to costly and catastrophic failures if not properly and timely addressed. This volume describes a wide spectrum of experimental and analytical studies, which provide a fairly comprehensive account of corrosion manifestations and methodologies for addressing them in structural and industrial design. As such, it is expected to make a valuable reference publication for engineers and scientists interested in the protection of structures and components from harmful and potentially ruinous corrosive action. The collected articles comprising this volume address issues which can be categorised into two main areas. The first is concerned with material science approaches to corrosion, that is, visual or instrumental means of assessing existing behaviour or effectiveness of corrective measures and techniques. The second part of the volume comprises boundary element simulations of cathodic protection schemes for the purpose of predicting and optimising their performance. A number of practical problems are analysed such as: the coating condition on a ballast tank wall; the impressed current cathodic protection of an offshore platform and minimizing a ship’s electric and magnetic signature. Topics covered include: Elemental identification; Material loss; Strain fields; Stress corrosion cracking; Corrosion resistance; Fretting corrosion; Contact surface damage; Electrochemical testing; Coating conditions; Cathodic protection; Current density distribution; Pipelines and deep well casings; Electric and magnetic signatures; Coating damage effects; Galvanic corrosion.

Download or read book Corrosion of Reinforcing Steel in Concrete written by D. E. Tonini and published by ASTM International. This book was released on 1980 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: