Cathodic Protection

This experimental field study interrupted the protection current offered by Impressed Current Cathodic Protection (ICCP) to ten in-service reinforced concrete structures. The study aimed to identify the long-term effects of ICCP after it was recognised that some of the systems are now reaching the end of their design life and require a significant level of maintenance. It was found that after five or more years of ICCP, the steel remained passive for at least 24 months after interrupting the protection current despite chloride contamination that would represent a corrosion risk.

The corrosion sensor should have high sensitivity enough to measure the corrosion rate in mild corrosive environments and the ability to detect the corrosion mechanism. Therefore, our goal is to develop and apply a steel thin film electrical resistance (TFER) sensor based on the measurement of changes in electrical resistance of the sensing elements in order to follow the corrosion of steel in a wide range of environments. The sensor with a thickness of 600 nm is fabricated by DC magnetron sputter deposition of steel on an Al2O3 substrate, followed by silk screen printing to improve the sensitivity of the sensor, especially to measure the corrosion rate in low corrosive environments such as anoxic corrosion in neutral solutions, steel protected by protective measures like a corrosion inhibitor or cathodic protection, and atmospheric corrosion. The sensor also has multiple-line sensing elements to detect the localized corrosion of steel. The TFER sensor is laboratory and field tested. All the studies demonstrate that the newly developed TFER sensor can be a promising and reliable tool for corrosion monitoring of steel exposed to various environments.

samples buried in soil have been studied in this research. Samples of unprotected carbon steel are used with other protected by different corrosion protection such as galvanic coating, rubber coating and two types of cathodic protection (impressed current and sacrificial anodes). The weight loss technique is used as a
function of the corrosion rate (mdd). The results, which have been obtained, show that the corrosion rates in the
unprotected samples are high compared with the  corrosion protected samples, and the maximum corrosion resistance is found to be at the cathodic protection
systems.

Pre-disturbance measurements of the in-situ corrosion properties of iron fittings on the snow brig James Matthews (1841) have been used as conservation management tools for the site. The wreck of the former slave trader is historically significant and the potential impact of continued industrial activities associated with nearby dredging activities necessitated in-situ cathodic protection of exposed iron fittings. A laboratory simulation study of the impact of pH and chloride content on the corrosion of cast iron and mild steel was conducted. There was a linear relationship between the corrosion rate of cast iron and the log of chloride ion concentration in the pH range 7.8< pH >5.5 with only a small pH effect noted for the given range of conditions. Studies on a 19th century mild steel sample indicated that the corrosion rate was linearly dependent on the square root of the chloride ion concentration and the corrosion rate fell in a linear fashion as the pH was increased to s...

The effect of zinc and tin addition to pure aluminum was investigated in 3 wt.% NaCl solution. The corrosion behavior of the elaborated samples (Al, Al–Zn and Al–Zn–Sn) was studied by open circuit potential, Tafel plot and electrochemical impedance spectroscopy. For the microstructure characterization, Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy were used. The aluminum activation increases in the following order: Al < Al–5Zn < Al–5Zn–0.1Sn < Al–5Zn–0.2Sn < Al–5Zn–0.4Sn. The impedance measurements and the microscopic observations confirmed the great activity of Al–Zn and Al–Zn–Sn compared to pure Al. The segregation at the grain boundaries leads to intergranular corrosion.

This book tries to collect the main ideas, techniques, and methods used by these prominent engineers in order to repair and rehab the large variety of structures. Furthermore, this book presents study cases of rehabilitation of structures such as bridges, buildings, garages, hotels and other exciting kind of structures. What is more, the book discuss about different types of construction as Pre-stressing, Post-tensioning, Cast-in-place, Pre-cast.

This article discusses the use of CP (cathodic protection) for the cost effective control of external well casing corrosion. CP is an important tool because maintaining casing integrity is essential to oil and gas production, water and gas injection, and gas storage fields. When a leak develops, production (or injection) usually ceases until the leak is repaired or a liner is installed. When corrosion is severe, the casing can collapse and the well may have to be abandoned, which can result in lost reserves. CP can be utilized in maintaining casing integrity caused by external corrosion, thereby reducing operating costs and maximizing total production and profits.

Corrosion Engineering–Principles and Solved Problems is based on the
author’s experience teaching undergraduate and graduate corrosion courses entitled Corrosion Engineering, Advanced Corrosion Engineering, and Electrochemical and Corrosion Techniques at the University of South Carolina. The book provides an extensive and in-depth theoretical analysis of thermodynamics kinetics, mass transfer, potential theory, and passivation, creating a foundation for understanding the electrochemical nature of the corrosion process and corrosion protection strategies discussed in the book’s second part. Around the world, the students who currently attend corrosion-engineering courses are enrolled in different engineering programs. This fact requires additional topics to be included in the book, and to this end, the book reviews the corrosion processes ,protection strategies, and testing for civil-engineering structures; corrosion in chemical process engineering; mechanical and nuclear corrosion engineering; and metallurgy. The fundamental principles of corrosion and related protection strategies are explained
through solved problems, exercises, and case studies, and the book helps upper-level undergraduate and graduate students learn the subject through an extensive theoretical description of corrosion theory, passivity, corrosion prevention strategies, and corrosion protection system design. The author has attempted to organize the book so the instructor can use it as the basis for a course in corrosion engineering for undergraduate students and also graduate students.

Build a rugged and portable device capable of performing NACE´s recommended indirect corrosion surveys. The equipment should be synchronized with a cathodic protection system through a GPS antenna. It should perform high-speed analog measurements and log the synchronized data.

This work aims to evaluate the effects of hydrogen in three high- strength steel grades. The phenomena of hydrogen (H) entry, transport and trapping inside the metals, together with the different types of damages due to the presence of hydrogen are presented. The study materials are a range of AHSS steel grades: Dual Phase Steel (DP 1000 and DP 1200) and Martensitic Steel (M 190). The hydrogen entry was performed by cathodic charging, which is suitable for industrial applications. In order to evaluate the influence of H on the steel mechanical properties, the following tests were done: H charging, to measure total H content (saturation point) and diffusible H content (embrittlement susceptibility); uniaxial tensile test of uncharged samples to determine notched tensile strength values and the strength levels at the end of elastic region and constant load tensile testing carried out in hydrogen environment, to determine the threshold values where hydrogen has an effect on the material. DP 1200 and M 190 were strongly affected by H pre-charging, as shown by the significant drop in stress required to break them. On the other hand, DP 1000 showed a lower embrittlement susceptibility, which is attributed to its lower mechanical strength. The current densities effects (0.2 up to 1.0 mA/cm²) were evaluated during H charging to measure diffusible H content. All steels showed a drop in the tensile strength i.e. experienced hydrogen embrittlement. Steels with higher tensile strength, as DP 1200 and M 190, showed a much bigger drop that is related to the favorable characteristics of martensitic microstructure regarding to the hydrogen permeability and diffusivity.

When cathodic protection is selected as a rehabilitation method for a concrete structure, there are many choices that can influence the type, effectiveness, durability and cost of the system. If the structure is complex in design and exposed to a dynamic environment, proper selection of the system components is important to suitable performance and longevity of the system. In particular, the cathodic protection system should be selected keeping in mind the owner‟s long term interests and maintenance capabilities. The purpose of this paper is to provide a general guideline to owners and design engineers for proper selection of cathodic protection systems to overcome corrosion problems on reinforced and prestressed concrete structures.

This project aimed to study a comprehensive conservation plan for archaeological iron in seawater using cathodic protection as the main conservation technique. Nine cast iron cannons were discovered in 2000 just off the coast of Marettimo island (Sicily, Italy), dated between 17th and 18th century at about 15m depth, dispersed as a consequence of the sinking of a Spanish ship. The fieldwork (2017-2018) investigated two cannons, C and D, to connect them to a cathodic protection system, study degradation processes and assess how the cleaning treatment could affect corrosion processes. An innovative cathodic protection system was designed to minimize its aesthetic and physical invasiveness and, throughout the project, measurements of surface potential in different points along the external surface of the cannons had been taken. Data-loggers were used to collect time series of temperature of the water and surface potentials. One of the two cannons chosen for this research was cleaned and then its potential measurements were compared to the other one that was not. The aim of this procedure was to make the archaeological objects more recognizable and easier to study for a larger audience by partly removing marine encrustations. By cleaning the surface, exposed metal could be sandblasted and eroded; thereby a protective layer was essential. A polipropilene geotextile was used to test how effective it was as physical barrier against erosion and biological growth.

The extent of corrosion between a miniature steel ship model at different relative velocities of sea water fitted with commercial sacrificial anodes of aluminium (Al) in sea water and magnesium (Mg) in fresh water is studied. The experimental results show that the degree of cathodic protection represented by the cathode potential at a given distance from different types of sacrificial anodes decreases slightly with an increase in the relative velocity. The results also show that the amount of Al or Mg required to protect the ship cathodically increases as the relative velocity increases.

Discovering the need for more dedicated work in the conservation field relating to the preservation of historic structures with iron content and their potential for catastrophic failure through hydrogen embrittlement. Covered only in the engineering field, preservationists need to rapidly awaken to the risks that cathodic protection and seawater exposure can have on imbed rebar and learn quickly how to halt any chance of hydrogen penetration into the structural matrix

In the present work electrochemical studies were carried out with disc electrodes of Fe–36Ni alloy in sulphate solution at pH 1?5, using linear voltammetry (LV) and electrochemical impedance spectroscopy (EIS) techniques, comparing the results with those of pure iron and pure nickel. The alloy shows a reduced corrosion when compared to pure iron, following the classical binary alloy behaviour where iron is preferentially dissolved (dealloyed) resulting in a nickel rich surface. The corrosion of Fe–36Ni alloy was further investigated under a thin electrolyte layer, where it was of interest to study the potential distribution as well as the variation of the electrochemical impedance as a function of the electrolyte film thickness. In this geometry, the corrosion current density, estimated from the low frequency (10 mHz) intercept of the EIS plot, decreases as the electrolyte thickness decreases below 500 mm, but does not change significantly while e is .500 mm.

Transmission lines are considered one of the major sources of magnetic field. In recent years electromagnetic field (EMF) interference with buried pipelines has been of great interest in the literature. The EMF interference on pipelines located in utility corridors is a real and serious problem which can place both operator safety and pipeline integrity at risk. Installing pipelines in energy utility corridors containing high-voltage AC transmission lines subjects the pipelines to induced AC voltages. This can be caused by an imbalance in the transmission system, and by high voltages near transmission tower grounding systems resulting from lightning strikes and phase faults. When a long-term induced AC voltage exists on a pipeline, it can be dangerous and potentially life-threatening for operations personnel to touch the pipeline or appurtenances. In addition, pipe corrosion also can result from AC discharge. Due to the wide lands of Saudi Arabia and its long water and oil pipelines...