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 (488KB)
Predicting the Performance of Cathodic Protection
Systems with Large Scale Interference
- Robert Adey, John Baynham, Tom Curtin
Understanding the interactions between
cathodic protection systems is becoming more complex
particularly in the marine and offshore industry. The
search for oil and gas in deeper waters and remote environments
has resulted in engineering designs with many components
on the sea bed as well as at the sea surface.
(1,387KB)
Predicting Corrosion Related Signatures
- Robert Adey and J.M.W. Baynham.
Computer simulation has been widely
used to predict the corrosion related electric and electromagnetic
signatures of naval vessels. The modelling strategy
has varied from simple dipole type models to detailed
boundary element models of the vessel and its environment.
(492KB)
Experimental Measurement and Computer Simulation of
Galvanic Corrosion of Magnesium Coupled to Steel
Jimmy X. Jia,Guangling Song
and Andrej Atrens, 2007
DOI: 10.1002/adem.200600206
(514KB)
Influence of geometry on galvanic corrosion of AZ91D
coupled to steel
Jimmy
X. Jia, Guangling Song, Andrej Atrens, 2006
DOI: 10.1016/j.corsci.2005.08.013
(15.9MB)
Power Point Presentation
- Validation and Optimising CP System Designs
E.
Santana-Diaz
(1.06MB)
A Complete
Underwater Electric and Magnetic Signature Scenario
Using Computational Modelling .
E. Santana-Diaz, R. Tims. Marelec,
April 2006
Computer modeling has been extensively
used to predict the performance of Cathodic Protection
systems, associated electric and magnetic signatures,
and Degaussing systems. This paper shows a complete
Underwater Electric and Magnetic Signature scenario
by combining the CRM in the water, the Hull Structure
Magnetic Field, and the Magnetic Field from the Earth's
Field Effect left over after Degaussing (DG ON), into
one comprehensive Underwater Magnetic Signature. New
approaches and computational tools, such as boundary
elements and optimization techniques, will be used together
to generate the complete scenario.
(504KB)
Simulation of galvanic corrosion of magnesium coupled
to a steel fastener in NaCl solution
J. X.
Jia, A. Atrens, G. Song and T. H. Muster, 2005
DOI: 10.1002/maco.200403855
(1.06MB)
Predicting
the Coating Condition on Ships Using ICCP System Data.
E. Santana-Diaz, R. Adey.
(409KB)
Evaluation of the BEASY program
using linear and piecewise linear approaches for the
boundary conditions
J
X Jia, A Atrens, D St John, J Baynham, G Chandler
Materials and Corrosion 2004, 55,
No 11 pp 845-852
The
boundary element method (BEM) was used to study galvanic
corrosion using linear and logarithmic boundary conditions.
The linear boundary condition was implemented by using
the linear approach and the piecewise linear approach.
The logarithmic boundary condition was implelement by
the piecewise linear approach. The calculated
potential and current density distribution were compared
with the prior analytical results.
(1.43 Mb)
Boundary Element Method Predictions
of the Influence of the Electrolyte on the Galvanic
Corrosion of AZ91D Coupled to Steel
J
X Jia, A Atrens, G Song
This
research investigated the galvanic corrosion of the
magnesium alloy AZ91D coupled to steel. The galvanic
current distribution was measured in 5% NaCl solution,
corrosive water and an auto coolant. The experimental
measurements were compared with predictions from a Boundary
Element Method (BEM) model. The boundary condition,
required as an input into the BEM model, needs to be
a polarization curve that accurately reflects the corrosion
process. Provided that the polarization curve does reflect
steady state, the BEM model is expected to be able to
reflect steady state galvanic corrosion.
(4.54Mb)
Predicting
the Effectiveness of Corrosion Control Measures Using
Computer Simulation
R
A Adey, E Santana Diaz
Maritime
Corrosion Conference, July 2004
(173KB)
Simulating
the Transient Response of ICCP Control Systems
JMW
Baynham, R A Adey Marelec,
March 2004
The
simulation of passive and active CP systems has over
the years become a straightforward matter so that it
is regularly performed to aid design and to assist understanding
of system behaviour. Such numerical simulation takes
into account the highly non-linear effects which take
place during corrosion. This paper describes the application
of CP simulation to modelling the dynamics of the complete
ICCP system, including controllers, generators, anodes
and reference cells.
(4.54Mb)
Computer
Simulation Of The Interference Between A Ship
And Docks Cathodic Protection Systems
R
A Adey, E Santana Diaz
NACE
Corrosion Conference, India, December 2003
Paint
and impressed current cathodic protection (ICCP) systems
are used to control corrosion on many different types
of structures. Since cathodic protection (CP) systems
were first applied, engineers have used experience and
intensive monitoring to optimise their design to prevent
corrosion. Numerical methods and in particular Boundary
Elements Methods (BEM) have been widely used in the
cathodic protection field to simulate the performance
of the CP system and to predict the associated electric
and magnetic fields.
(4.54Mb)
Predictive Modelling of
Corrosion and Cathodic Protection Systems
R
A Adey, E Santana Diaz
Tri-Service
Corrosion Conference, USA, November 2003
Computer
based modeling tools have developed in recent years
to the stage where they are routinely used to assess
the performance of corrosion control measures for naval
ships and boats and critical parts of the infrastructure.
They are also used to predict the important associated
electric and magnetic fields induced by the corrosion
related currents. Computer modeling enables the designer
to build a virtual prototype of the ship or structure
and predict how the corrosion control measures will
perform over under various operational conditions.
(254KB)
A
combined design methodology for impressed current cathodic
protection systems
V.G. DeGiorgi, E.D. Thomas II, K.E. Lucas, A. Kee
The
corrosion prevention capability of shipboard impressed
current cathodic protection systems are effected by
the geometry of the ship hull, conductivity of the surrounding
water, material polarization response and any material
interactions. Changes in system configuration and service
environment from those used in design analysis require
the capability to analyze system performance under varied
circumstances. While individually limited, experimental
scale modeling and computational boundary element modeling
techniques can be used in concert to design a robust
system and to provide a means for quick analysis of
system and environmental changes.
(189KB)
Coating
integrity effects on impressed current cathodic protection
system parameters
V.G. DeGiorgi, C.P. Hamilton
A
computational study of the changes in electrical current
requirements due to damage to the corrosion preventative
coating on the propellers of a U. S. Navy ship is performed.
Coating damage is modeled using effective coating efficiency.
The boundary element model used has been previously
validated by comparison with physical scale modeling
experimental results. Trends for higher current demand
and lower potential at key locations with increasing
levels of damage are presented.
(175KB)
Influence
of Seawater Composition on Corrosion Prevention System
Parameters
V. G. DeGiorgi
Cathodic
protection systems, such as those designed for ships,
utilize material electrochemical properties to minimize
corrosion damage. The extent of material interaction
in the corrosion process is partially dependent on the
resistivity of the surrounding medium. A medium with
low resistivity, such as seawater, provides a greater
degree of electrical connectivity than a medium of higher
resistivity.
(347KB)
Boundary
Element Evaluation of ICCP Systems Under Simulated Service
Conditions
V.G. DeGiorgi, K.E. Lucas, E.D. Thomas II, M.J. Shimko
The
purpose of this work was to evaluate multiple material
surface ship models and compare results, when possible,
with scale model experimental results.
(399KB)
Characterization
accuracy in modeling of corrosion systems
V.G. DeGiorgi, A. Kee, E.D. Thomas
Boundary
element techniques are well suited for the solution
of LaPlace’s equation in semi-infinite and infinite
volumes. As in any computer modeling, issues must be
addressed in the early stages of the analysis for the
finished work to be an accurate evaluation of the system.
The goal of the analysis must be clearly defined; preliminary
and trend analyses often require less mesh refinement
than detailed system evaluations. The work presented
is a portion of a detailed evaluation of the impressed
current cathodic protection system of an U S Navy CG
class surface ship.
(488KB)
Computer
Simulation as an aid to CP System Design and Interference
Prediction
Robert Adey, John Baynham
Cathodic
protection (CP) systems are commonly designed by estimating
the overall current demand and then developing an anode
configuration sufficient to protect the structure. To
a large extent the performance of a CP system is dependent
on the skill and experience of the corrosion specialist.
As the underground infrastructure becomes more complex
these traditional approaches may become less reliable.
In an increasingly complex underground infrastructure,
stray currents from other sources (such as parallel
or crossing pipelines, industrial plants, or electric
rail transit facilities) can come into contact with
the underground steel structures.
(1,222KB)
Applications
of Boundary Elements in corrosion engineering
R.A. Adey, C.A. Brebbia, S.M. Niku
In
recent years there has been a growing interest in the
prediction of the behaviour of engineering problems
involving galvanic effects. This class of problem includes
galvanic corrosion, cathodic protection methods and
the inverse problem of electro- deposition commonly
used in manufacturing. This article will concern how
a computer software system based on boundary elements
can be used to accurately simulate this class of problem.
(729KB)
Computer
aided design of cathodic protection systems
R.A. Adey, S.M. Niku, C.A. Brebbia, J Finnegan
The
design of cathodic protection systems has , like many
engineering specialties, developed as an art where the
corrosion engineer uses his skill and experience to
produce a satisfactory design. The simple formulae which
are used as part of the design process have been used
skilfully but the whole scheme has been usually supported
by high factors of safety. With the development of complex
marine structures associated with the energy industry
researchers became interested in more accurate methods
of predicting the behaviour of cathodic protection systems.
(58KB)
Corrosion
basics and computer modelling
V.G. DeGiorgi
Corrosion
is the destruction of material resulting from exposure
and interaction with the environment. While common usage
typically associates corrosion with metals, the destruction
of non-metallic materials as a result of exposure to
the environment can be considered corrosion; the disintegration
of plastics when exposed to sunlight and the rotting
of wood are examples of non-metallic corrosion. However,
the concern of this chapter is corrosion of metals,
especially electrochemical corrosion, and the ability
to use computer modeling techniques to predict corrosion.
(313KB)
Analysis
of stray current corrosion problems using boundary element
method
J. Trevelyan and H.P. Hack
Today’s
offshore and ocean going structures and buried structures
are fitted with systems which work to inhibit the rate
at which the structure corrodes in the aggressive marine
or soil environment. These operate by setting up an
electrostatic field in the water surrounding the structure
which causes a desired voltage and current density distribution
over its surface area. These cathodic protection (CP)
systems are carefully designed to offer the structure
a uniform protection over its surface with the most
economical use of anodes.
(165KB)
Computer
prediction of stray current corrosion
G.E. Strong, R.A. Adey, R.S. Rudas
The
likelihood of CP interference on steel structures located
in proximity to large cathodically protected chemical
storage tanks was evaluated using one of the latest
computer modelling techniques. Application of the Boundary
Element Analysis System (BEASY) allowed CP interference
to be assessed in terms of current density, which is
directly proportional to the corrosion rate, rather
than having to use the qualitative approach of measuring
the potential shift of the soil. Furthermore, the computer
modelling approach enables results to be obtained at
the design stage, allowing CP systems to be optimised
so that interference is minimised.
(964KB)
A
'CAD' system for the analysis and design of cathodic
protection systems
S.M. Niku, R.A. Adey, Chapter 13, PLANT CORROSION:
Prediction of Materials
Performance, Ed, J.E. Strutt, J.R. Nicolls, Institution
of Corrosion Science and Technology.
The accurate analysis of the Cathodic Protection System
without the aid of computerized techniques is an impossible
task due to the complexity of the geometry and environmental
conditions which are typical characteristics of most
practical problems. The design based on the traditional
scheme involves only the overall current requirement.
It does not consider geometry details or polarization
on the surface of the structure, and therefore is highly
dependent upon the skill and experience of the corrosion
engineer.
Following the growing interest in computer modelling
of corrosion problems in recent years, few computer
programs have been developed.
(539KB)
Finite
resistivity and shipboard corrosion prevention system
performance
V.G. DeGiorgi
In
the computational evaluation of electrochemical corrosion
systems painted surfaces are often treated as perfectly
insulated. While many paint systems have a high resistance;
the resistance in finite rather than infinite. In this
work a range of finite resistivity values will be assigned
to the painted surfaces in a boundary element model
of a shipboard ICCP system. The studies performed were
developed to provide an increasing understanding of
the effects of finite resistivity on system performance,
provide a quantitative measure of the effects of ranges
of finite paint on system performance and to increase
the understanding of modeling methods to issues of damage
and material polarization response definitions.
Computer
Modelling at NACE - Corrosion 99 Conference
At
the recent National Association of Corrosion Engineers
(NACE) Conference in San Antonio, Texas, a special session
was devoted to Computer Modelling in corrosion control.
BEASY and three BEASY users presented papers describing
applications of modelling to solve corrosion control
problems. Applications included ICCP modelling of ships
and boats, design of CP systems for offshore oil and
gas facilities and modelling of pipelines and underground
infrastructure. It was clear from the meeting that computer
modelling has matured as a technology for modelling
ships and marine structures and is now widely used.
With the ability to perform modelling on PC's, the technology
can now be used to solve a much wider range of corrosion
control problems (e.g. pipelines, underground facilities).
The
papers presented were:
(168KB)
Computer
Simulation as an Aid to Corrosion Control and Reduction:
Robert A Adey & Pei Yuan Hang
(986KB)
Examination
of Modeling Assumptions for Impressed Current Cathodic
Protection Systems
V
G DeGiorgi, A Kee, K E Lucas & E D Thomas
(596KB)
Boundary
Element Modeling of Galvanic Anode Cathodic Protection
Using the Design Slope Method
D W Townley
(550KB)
Computer
Modelling of Offshore CP Systems for 15 Years: What
Have We Learned?
Per Olas Gartland, Frode Bjoernaas & Harald Osvoll
(539KB)
Virginia DeGiorgi from the Naval Research Laboratory
in Washington recently published a paper discussing
how paint and coatings can be represented in BEASY cathodic
protection system models.
(884KB)
The
effect of protective coatings on galvanic corrosion
for bolted components
K.S. Yeung
The
increasing demands for better fuel-efficiency have led
the automobile industry to use lightweight metals such
as aluminum and magnesium in conjunction with conventional
metals such as steel. Galvanic corrosion is the unfortunate
result of this “mixed metals” usage. The automobile
companies rely primarily on proving ground testing to
evaluate the severity of corrosion. Such a procedure
is costly and time consuming. The objective of this
project is to explore the feasibility of using computer
simulation to predict galvanic corrosion in automobile
environments. The BEASY code has been chosen for this
project.
(265KB)
BEM
application for thin electrolyte corrosion problem
Y.-G. Kim, Y.-C. Kim & Y.-T. Kho
BEM
methods were applied for a thin electrolyte problem.
Al-Z%Zn alloy thermal spray coatings are used for seawater
heat exchanger made of AI-MS alloy for LNG process utility.
We investigated the remaining service life of the coating.
The sprayed coating was acting as a sacrificial anode.
The integrity of the coating degraded with time by peeling-off
and thinning. The expected life of the coating is a
crucial data for maintenance scheduling. The distribution
of the corrosion potential and current were calculated
with BEM analysis with BEASY CP 7.0 module. The anodic
behavior of the coating was changed significantly by
polymer sealing over-coating and the resultant remaining
service life.
(343KB)
Design
andOptimisation
of cathodic protection Systems Using Computer Similation
Robert Adey and John Baynham
NACE’s
Annual Conference, Corrosion/2000, March 2000, Orlando,
Florida
The
design of cathodic protection systems normally relies
on a combination of experience, experimental data and
heuristics. However, problems and failures of CP systems
not only has an economic cost, it can also present a
threat to life and the environment. This paper will
describe the application of a software system designed
to simulate the performance of cathodic protection systems
and predict the impact of the design parameters and
the environment on its performance.
4.1
Defence Applications
(461KB)
Predicting
the hull state from information of potential measurements
of the hull
Damages
appear on a hull of a vessel during its lifetime. In
many cases the correct position of these damages are
completely unknown. Its knowledge is important from
mainly two points of view.
(55KB)
Underwater
Electrical Potential
BEASY
Corrosion and CP predicts the corrosion of ships, offshore
structures, storage tanks, corrosion, pipelines etc.
and the effectiveness of Protection Systems. It also
predicts the near and far field underwater electric
potential (UEP) “signature” of ships and boats.
(378KB)
A
Computational Environment for the Optimisation of CP
system Performance and Signatures
E. Santana Diaz, R.A. Adey, WARSHIP 2001
In
this paper an integrated set of computational tools
are described which predict the level of protection
of a vessel, the associated electric and magnetic signatures
and automatically optimisation of the anodes to achieve
the desired characteristics of the vessel. The approach
adopted was to couple the BEM model of the corrosion
electrode kinetics and sea- water electric field with
an optimisation algorithm.
(323KB) Optimisation
of ICCP systems to minimise electric signatures
E. Santana Diaz, R.A. Adey, J. Baynham,Y. H. Pei,
MARELEC 2001
In
this paper an approach to the automatic optimisation
of the ICCP system is presented. The objective being to design the system to
minimise the electric field while at the same time provide
adequate protection.
The approach adopted was to couple the BEM model
of the corrosion electrode kinetics and sea water electric
field with an optimisation algorithm.
A user interface has also been developed to enable
modelling and optimisation tasks to be performed quickly
without the necessity of detailed changes to the BEM
model.
(232KB)
Predicting
corrosion related electrical and magnetic fields using
BEM
Robert Adey, John Baynham, UDT Europe 2000
Computer
models have for some years been used to predict the
performance of ICCP systems on ships and boats. The
objective being to achieve optimum protection of the
vessel from corrosion and to predict the associated
fields/signatures. However, in many cases these models
have been based on simple dipole approximations. In
this paper a new system is described which integrates
the electric and magnetic models to provide a tool capable
of accurately predicting the impact of any change in
the ICCP system, surface conditions or environmental
conditions on the electric and magnetic signatures.
4.2
Polarisation Data
(2,567KB)
Atlas
of polarization diagrams for naval materials in seawater
Harvey P. Hack , CARDIVNSWC-TR-61-94/44
Polarization
curves were developed in seawater at low (quiescent)
flow and at 2.4 m/s flow for nine structural alloys.
Potentiostatically generated curves for up to 120 days
are compared with potentiodynamically generated curves
at four scan rates with freely corroding pre-exposures
of 1 or 120 days. Smoothed curves successjidly used
in computer model predictions of cathodic protection
current and potential distributions are also presented.
4.3
Concrete
(314KB)
Macrocell
Corrosion of Steel in Concrete - Experiments and Numerical
Modelling
S. Jaggi, H. Bohni, B. Elsener
Macrocell
corrosion with a local anode and a large cathode frequently
occurs in chloride indeuced corrosion of rebars in concrete
and is responsible for very high local corrosion attacks
and reduction in cross section of the rebars found.
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