Detecting Corrosion in Oil Pipeline using Capacitor

Internal-pipeline corrosion is a serious issue in oil and gas industry. This project aims to build a capacitive sensor using aluminium plates and analyzed the effect on the output voltage when corrosion occurred in the pipeline which carries different viscosities of oil. Corrosion in the oil pipeline affects the quality of liquid in it and causes leakage which pollutes the environment. It is time and cost consuming to replace the pipeline and the operators find it difficult to assess the condition inside the pipelines. This project covers only the oil pipeline and three types of oil with different viscosity are used to demonstrate the working principle of the capacitive detector. Simulation was done to verify the effects of capacitance to the output voltage. Iron(II) ion and iron(III) ion which are the products of early stage corrosion and rusting process respectively were added into the oil and readings were taken and recorded for analysis. Experiments were conducted to analyze the effect of different levels of corrosion i.e. early stage and rusting stage towards the output voltage. Based on the results obtained, the output voltage across the capacitive plates decreases as more iron ion present in the oil. The outcome from the comparison between early stage of corrosion and rusting stage were also done and the outcome was that the output voltage across the capacitive plates is lower in the rusting stage. Thus it can be concluded that the more severe is the corrosion in the pipeline, the lower is the output voltage measured across the capacitive plates

Mechanisms of the Atmospheric Corrosion of Weathering Steel.

The atmospheric corrosion mechanisms of weathering steel have been investigated through the use of both field and laboratory techniques. Laboratory techniques included time-transformation studies of the oxide-hydroxides (gamma)-FeOOH and (beta)-FeOOH under controlled temperature conditions in air and in vaccum, as well as electrochemical testing for the characterization of the dissolution and film formation kinetics. Potentiostatic tests with set potentials in the immediate vicinity of the open circuit potential of the weathering steel were found to simulate very well the conditions of atmospheric exposure. 0.1% NaCl solutions as well as other concentrations were generally used for comparison purposes. The specific adsorption of chloride ions from the solution were found to have a significant influence on the rate of dissolution of the steel. The rate of change of the current with time(m) was determined at various settings. Potentiodynamic tests were done to verify the dissolution mechanism of weathering steel in chloride media. The effect of the surface treatment of the phosphoric acid inhibitor was also investigated using the same techniques. The infrared spectroscopic technique was successfully utilised to follow the phase transformations of the Fe-H(,2)O system both in the laboratory and in field exposure testing. The transformations of akagaenite and lepidocrocite to haematite were confirmed but a previously unreported intermediate, the hydrated maghamite, was found. Ferrihydride was found to occur in rural atmospheres

Influence of NaCl deposition on Atmospheric Corrosion of Carbon Steel

Atmospheric corrosion can be defined as the corrosion of materials exposed to air and its pollutants rather than immersed in a liquid. Regularity of the initial atmospheric corrosion of carbon steel in the presence of NaCl was investigated. The result shows that Sodium Chloride (NaCl) can accelerate the corrosion of carbon steel. Dry mass gain of carbon steel in the presence of NaCl increases with exposure of time, which can be correlated by using experimental decay function. The relation of dry mass gain and amount of NaCl deposition at certain time follows a quadratic function. More amount of NaCl deposition would slow down the corrosion rate to some extent after exposure for a certain time. The experiment was conducted to measure the corrosion rate of the metal which was exposed to the environment of different concentration (%) of NaCl. The exposure time was set to four weeks for each concentration and the data was analyzed. The data was gathered in a table and graph was plotted to show the relationship of the NaCl deposition on the sample. From the analysis, the results show that the NaCl deposition increased with the increasing of exposure time. This is because of the electrochemical process that takes places on the surface of the carbon steel

Electrochemical Impedance Spectroscopy (EIS): A Review Study of Basic Aspects of the Corrosion Mechanism Applied to Steels

AC impedance measurements have been applied for over twenty years in electrochemistry and physics to investigate the electrical properties of conductive materials and their interfaces using an external electrical impulse (VOLTAGE, V or CURRENT, I) as driving force. Furthermore, its application has recently appeared to be destined in the Biotechnology field as an effective tool for rapid microbiologic diagnosis of living organism in situ. However, there is no doubt that the electrochemical impedance spectroscopy (EIS) is still one of the most useful techniques around the world for metal corrosion control and its monitoring. Corrosion has long been recognized as one of the most expensive stumbling blocks that concern many industries and government agencies, because it is a steel destructive phenomenon that occurs due to the chemical interaction with aqueous environments and takes place at the interface between metal and electrolyte producing an electrical charge transfer or ion diffusion process. Consequently, it is experimentally possible to determine through the EIS technique the mechanism and control that kinectics of corrosion reactions encounter. First, EIS data is collected through a potentiostat/ galvanostat apparatus. After, it is fitted to a mathematical model (i.e. an equivalent electrical circuit, EEC) for its interpretation and analysis, fundamentally seeking a meaningful physical interpretation. Finally, this review reports some basic aspects of the corrosion mechanism applied to steels through the experimental EIS response using Nyquist or Bode plots. Examples are given for different applied electrochemical impedance cases in which steel is under study intentionally exposed to a corrosive aqueous solution by applying a sinusoidal potential at various test conditions

Recent Researches in Corrosion Evaluation and Protection

The purpose of this book is to present and discuss the recent methods in corrosion evaluation and protection. The book contains six chapters. The aim of Chapter 1 is to demonstrate that Electrochemical Impedance Spectroscopy can be a very useful tool to provide a complete evaluation of the corrosion protection properties of electro-coatings. Chapter 2 presents results of studies of materials degradation from experimental electrochemical tests and theoretical calculations. Chapter 3 deals with the presentation of the corrosion and corrosion prevention of the aluminum alloys by organic coatings and inhibitors. Chapter 4 addresses the new method of pigment preparation that can improve protection efficiency. The effectiveness of plasma deposited films on the improvement of carbon steel corrosion resistance is discussed in Chapter 5. Chapter 6 deals with the conjugation of carbon nanotubes with organic-inorganic hybrid to prepare hybrid coatings that combine high anti-corrosion efficiency with elevated mechanical resistance

Localized corrosion and component failures: Causes, mechanism and remedial measures

Amongst the various types of failures of the components caused due to corrosion, a majority of them are attributed to localized type of attack of the environments on the surfaces of metals/alloys. The present talk incorporates the discussions on causes, mechanism and remedial measures adopted to control the localized type of corrosion attack. Initially, a brief background about the theoretical aspects of corrosion of metals is given. This includes the various types of cells that cause corrosion of metals and also about the thermodynamical approach to understand the phenomenon of corrosion. The subjects related to five types of localized corrosion, namely pitting, crevice, stress corrosion cracking, corrosion fatigue and intergranular corrosion, who are considered to be the most dangerous type and cause catastrophic failures, are discussed a bit in detail. Their mechanism, causes and remedial measures adopted to control the problems are described. The lecture also touches in brief, the principles involved in failure investigations. This describes the importance of site visit, collection of sample of corrosion products, visual observations, mechanical and chemical tests and fractographic studies. Finally, some examples of case studies of failed components are incorporated to illustrate the application of knowledge in pinpointing the causes of failures and suggest the remedial measures to avoid the recur¬rences of such failures

Electrochemical Techniques for Corrosion and Tribocorrosion Monitoring: Fundamentals of Electrolytic Corrosion

This first chapter aims at giving a brief framework for understanding the principles of electrochemistry in corrosion and tribocorrosion, enabling potential users and readers to quickly apprehend the electrochemical nature of corrosion. The subsequent chapter will provide additional details on the methods derived from these principles in a clear manner and ready-to-use format. In particular, the implementation of electrochemical techniques for the study of tribocorrosion allows, in situ and in real time, to monitor and control the corrosion conditions during wear and to quantify the corrosion kinetics. An introductory to some of the basic terms and concepts of electrochemistry and corrosion is first presented. Then, an overview of the thermodynamic and kinetic parameters of relevance to corrosion electrochemistry is highlighted. A description on how the electrical nature of corrosion reactions allows the interface to be modeled as an electrical circuit, as well as how this electrical circuit can be used to obtain information on corrosion rates. These prerequisites are necessary to better understand the surface reactivity of metals and other electronic conductive materials immersed in ionic electrolyte media whether or not subjected to mechanical stimuli

Modelling the localized corrosion effects experienced by electroplated zinc and zinc - 4.5 wt.% aluminium steel coatings.

A general modelling approach is described for the numerical simulation of localized corrosion phenomena. The model is demonstrated using several simple cases and compared both to analytical solutions and experimental measurements. The model is intended to operate at the microscopic-mesoscopic length scales and involves two- or three-dimensional field calculations performed in a finite difference computational framework. Limitations and possible extensions to the algorithm are discussed. Experimental work has been reported that demonstrates the effects of microstructural variations within Zn-Al Galfan type coatings on the corrosion behaviour of cut-edge material, i.e. those cases where both the underlying steel and the organic coated Galfan layer are simultaneously exposed to a corrosive environment. An attempt to model the localized corrosion effects in electroplated zinc and hot-dip Galfan coatings has been made. The model combines both diffusive and electrochemical phenomena and describes corrosion effects on micro scale coating layers in NaCl electrolyte. The model predicts the 3D form of electrical potential, localized current densities and concentrations and also the time-dependent degradation of the micro scale coating layer. Results of the prototype model are quantitatively compared with measured current densities obtained from Scanning Vibrating Electrode Technique (SVET) studies. Simulations have been performed to predict the microstructural influence on the corrosion of Galfan coatings cooled at different rates. The model is in good agreement with experimental findings with respect to the cut-edge behaviour of these coatings, although contradicts those SVET measurements made in respect of the surface corrosion performance

Influence of NaCl deposition on Atmospheric Corrosion of Carbon Steel

Atmospheric corrosion can be defined as the corrosion of materials exposed to air and its pollutants rather than immersed in a liquid. Regularity of the initial atmospheric corrosion of carbon steel in the presence of NaCl was investigated. The result shows that Sodium Chloride (NaCl) can accelerate the corrosion of carbon steel. Dry mass gain of carbon steel in the presence of NaCl increases with exposure of time, which can be correlated by using experimental decay function. The relation of dry mass gain and amount of NaCl deposition at certain time follows a quadratic function. More amount of NaCl deposition would slow down the corrosion rate to some extent after exposure for a certain time. The experiment was conducted to measure the corrosion rate of the metal which was exposed to the environment of different concentration (%) of NaCl. The exposure time was set to four weeks for each concentration and the data was analyzed. The data was gathered in a table and graph was plotted to show the relationship of the NaCl deposition on the sample. From the analysis, the results show that the NaCl deposition increased with the increasing of exposure time. This is because of the electrochemical process that takes places on the surface of the carbon steel

Scoping Study of the Effects of Aging on Landmines phase 2

Most of the mines that currently threaten populations were manufactured more than 50 years ago and many have been in the ground for 30 years or more. Despite the inevitable and obvious deterioration, there has been very little research into the effects of aging on landmines. In 2008, James Madison University (JMU), the Center for International Stabilization and Recovery (CISR), and C King Associates Ltd (CKA) began a study designed to understand the aging process and the range of implications for the various components of mine action. The two-and-a-half year study was funded by grants from the US Department of State, Bureau of Political-Military Affairs/Office of Weapons Removal and Abatement