Corrosion Simulation Newsletter
BEASY will once again be attending the annual NACE Corrosion Conference, which this year is being held Phoenix from April 15th -19th 2018. We will be active in both the conference program and exhibit hall showing our corrosion modelling services and software.
We welcome you to come and visit our booth (No 1512) to find out more about the capabilities of BEASY simulation products, or how BEASY modelling services can provide the solutions you need. Alternatively to make an appointment to meet us at the conference, or to obtain further information, please contact us
Comparison of Resistance to Cathode with Resistance to Ground in the Marine Environment
By John Baynham and Tim Froome
John and Tims paper at NACE 2018 focuses on the calculation of Anode resistance which is a fundamentally important quantity which is used in all CP system design work in the marine environment.
Established methods for calculation of anode resistance determine the resistance through the electrolyte between the anode surface and ground (or “remote earth”), and are based on analytical or approximate formulas. Such formulas are generally based on simplified anode geometry, such as long thin cylindrical bars, and may include effects of interference between multiple such bars grouped in fairly simple geometric patterns. Resistance to ground of real anode shapes may be very different from formula-based predictions even for single anodes, and computer-based simulation methods are now available to determine resistance to ground both readily and more accurately.
To obtain further information, please contact us
Predicting Aircraft Corrosion
Atmospheric Corrosion Measurements to Improve Understanding of Galvanic Corrosion of Aircraft
Matthew Merrill, Mark Kim, Fritz Friedersdorf from Luna Innovations and Thomas Curtin, Robert Adey from BEASY
Fritz will present the paper at NACE 2018. Atmospheric corrosion represents an annual multi-billion dollar cost burden for the aerospace and defense sectors. For many aircraft, particularly those operating in marine environments, up to ninety percent of corrosion is due to galvanic interactions at dissimilar metal couples. As new materials are introduced with the acquisition of more advanced aircraft, galvanic corrosion is likely to remain a concern. The ability to model galvanic corrosion accurately holds out promise of being able to not only predict the performance of new material combinations and guide material selection but also to predict corrosion damage to optimize maintenance.
A segmented, galvanic sensor is presented that enables the quantification of spatial distributions of galvanic current under thin film conditions that can be compared to model predictions for verification and to judge the suitability of immersion versus thin-film electrolyte data inputs.
To obtain further information, please contact us
In early 2017 at the NACE Corrosion Conference in New Orleans BEASY staff presented some recent developments and applications in the technical sessions and exchange groups. It was great to meet many friends at the conference and discuss how modelling can be used to improve and optimize CP systems as well as providing further confidence in their performance.
Assessment of Effects of Cavities and Narrow Channels on CP Design in the Marine Environment
Underwater termination assembly, mud mat, split casing, armour
termination and bend limiters being readied for deployment.
At this year NACE John Baynham and Tim Froome presented an interesting paper on the difficulties presented by the geometry of certain structures in obtaining adequate CP protection.
CP system design work in the marine environment makes use of structure surface area, required current density, and anode resistance formulae to select the number and mass of anodes required to protect a structure. These formulas do not take account of restrictions to current flow caused by close proximity of structural surfaces to each other, and consequently CP systems which have been designed in the recommended way may sometimes not protect parts of a structure.
This paper investigates the protection provided to the structure when cavities and narrow channels/annuli are present, and identifies patterns of behaviour. A series of computer-based parameter studies was performed in which, for example, separation between two structural surfaces is varied, and the extent of the protected area is determined. The paper also investigates effects of geometry on current flowing through a hole in a plate. This situation frequently occurs in design of mud-mats - when the interest is to determine current drain to buried surfaces, and sometime occurs when free flooding cavities need to be protected. Again computer-based studies are used, and for example the size of the hole is varied.
For further information please contact us
There were a number of papers published this year which featured BEASY modelling.
Optimization of the quantity, locations and output currents of anodes to improve cathodic protection effect of semi-submersible crane vessel
S.H.Xing, Y.Li, China University of Petroleum, Qingdao. H.Q.Song, Y.G.Yan, M.X.Sun. Luoyang Ship Material Research Institute, Qingdao
Potential profiles on SSCV after optimization for the different cases considered which represent the loading of the crane and the coating condition
In this paper published in the Journal Ocean Engineering a 3-D boundary element model of a semi-submersible crane vessel (SSCV) is combined with movement of anodes and adjustment of currents to optimize the anode quantity and location. The protection in four different states of the crane vessel representing the loading and coating condition were predicted and the simulation results indicate that the SSCV is well protected for the whole service life when the protective coating on the hull is repainted every seven years.
For further information, please contact us.
Optimization of the Cathodic Protection Design in Consideration of the Temperature Variation for Offshore Structures
M. S. Hong, J.-H. Hwang and J.H. Kim. Hyundai Heavy Industries Co., Ltd.,
Optimized simulation results of FPSO: (a) ﬁnal stage at 5°C and (b) ﬁnal stage at 28°C.
In this study published in Corrosion, electrochemical tests were performed to obtain the carbon steel (EH36; UNS K12821(1)) cathodic polarization curves which contained environmental information under tropical (28°C) and arctic (5°C) environment model conditions, and the surface morphology was analyzed after the potentiostatic polarization test using scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS).
Based on the polarization data, a computational analysis was conducted to verify and optimize the CP design of the floating production storage and offloading (FPSO).
For further information, please contact us
BEASY is working on a project supported by the United States Navy Sea Based Aviation Program and the Air Force to validate and develop computational corrosion modelling tools which can be used to predict the location and severity of corrosion within aircraft structures. The increased use by engineers of corrosion simulation tools during design and maintenance has the aim of improving the durability of an aircraft through better material selection, improved corrosion resistant design, and better predictive maintenance schemes. Improved aircraft durability will ultimately reduce fleet maintenance and life-cycle corrosion costs.
Experimental test configuration with an Aluminum plate connected to an Stainless Steel Plate.
The plates are segmented so that the distribution of current can be measured
The work is building upon the BEASY Corrosion Manager software and is extending this technology to predict the long term galvanic corrosion risk to structures. We envision that this modelling technology will support a radical change in design philosophy for aircraft and other vehicle structures by providing engineers with corrosion simulation tools needed for current and future corrosion challenges.
In conjunction with Luna Innovations Inc and the University of Virginia experimental tests have been performed to validate the galvanic corrosion models under "bulk" electrolytes and thin film conditions. For example good agreement has been obtained across a range of electrolyte film thicknesses comparing measured and model predictions of the corrosion current density distribution across a segmented electrode test specimen as shown in the figures. Details of this study will be published NACE Corrosion 2018.
BEASY once again attended the annual NACE Corrosion Conference, which this year was held between March 26-30, 2017 in New Orleans, Louisiana.
We were active in both the conference programme and exhibit hall showing our modelling services and software to support engineers with responsibility for corrosion aspects related to offshore and onshore structures, and also in the wider manufactured sector (aircraft, vehicles, etc).
Predicting The Impact Of Interference On the Corrosion Control Of Offshore Oil & Gas Assets
Designing and operating cathodic protection (CP) systems to protect oil and gas structures from corrosion in offshore marine environments is a complex task as interference can degrade the protection provided and accelerate anode depletion. Modern developments frequently consist of connected assets like well casings, seabed flow lines, pipelines, well-head structures, risers, and surface vessels such as floating production, storage, and offloading (FPSO) units.
Although these structures are often separated by large distances, the relatively low resistance of seawater means they pose the potential to interfere with each other and significantly affect the overall performance of a CP system. Computer modelling technologies provide improved predictions of CP system performance and identify the risks of interference.
Mitigating Pipeline Interference From DC Railways
Mitigating Pipeline Interference From DC Railways Predictive modelling can play a significant role in the design, planning and operation of cathodic protection systems used to protect pipelines. It can also be used to verify the protection provided, inform selection of an optimum design and assess and facilitate assessment and mitigation of interference from third parties such as railways etc.
The problem of stray current interference from railway, metro and tram sources is a growing concern as it may cause pipeline corrosion resulting in environmental pollution, unsafe operations, and reduction of the pipeline service life.
These are just some of the applications we will be discussing and presenting at NACE 2017. Please come and visit us at booth 2027, or if you would like to set up a meeting to discuss any aspect of BEASY's modelling and software services, please contact us
BEASY were again at EUROCORR this year which was held in Montpellier, France, and we presented a number of papers on subjects including Internal Cathodic Protection of Offshore Sea Water Pump Caissons, Modelling Cathodic Protection/Prevention of Reinforcement in Concrete, and Using Predicted Corrosion Damage to Determine Stress Concentration, Fracture and Crack Growth. Tim Froome was on hand to discuss both the papers and applications of BEASY modelling.
Seminar Programme China
BEASY in conjunction with Beijing Safetech Pipeline Co., Ltd recently presented a popular series of seminars in China on Cathodic Protection and Interference Modelling
Bob Adey introducing BEASY and a series of
CP Modelling & Interference Case Studies at the seminar in Chengdu
If you are interested in this subject or need help and advice about interference, then please contact us for more information.
New Case Studies
BEASY have recently published two new Case Study data sheets.
Case Study: Interference Between A Pipeline & A DC Railway Metro System
Interference Between A Pipeline & A DC Railway Metro System A planned metro line with a car parking yard and ten traction zones is to be constructed. The line will cross an existing oil pipeline within 9m of a traction zone. It will run parallel with the metro car parking yard at a separation of about 40m for several hundred metres. A stray current interference assessment is required to evaluate the interference level and how to mitigate it if an unacceptable interference is found to occur.
A model is used to predict the protection provided by the CP system and the interference between the pipeline and the metro system under different operating conditions
Case Study: HVDC Interference On Pipelines HVDC Interference On Pipelines
A new HVDC transmission line is being planned with a voltage of ±500kV and a distance of 577 km. The distance of one planned electrode from a nearby constructed pipeline is about 9 km. The pipeline is likely susceptible to interference from the HVDC systems. There is a need to assess the interference level and its risk, and the feasibility of mitigation.
A simulation model was used to predict and quantify the interference caused by the system operating under bipolar conditions where the HVDC ground electrodes may pick-up current from the ground or discharge current into the ground. Mitigation measures were also investigated.