Papers and Presentations
Engineers have long known that the old methods of corrosion prediction (e.g. galvanic tables) and testing (ASTM B117) are inadequate and inaccurate. New capabilities for computational corrosion prediction are improved in order to exactly understand how the corrosion occurs and how severe it will be; and with that information to design more durable systems. The aim of the session was to provide a discussion Forum to share information and ideas on corrosion modeling and testing so as to predict and minimize corrosion in complex systems. The Forum brought attendees up to speed with developments in the area of corrosion prediction and test development and raise awareness of changes in the MIL-STD-889 specification and how this will impact design methods.
- Victor Rodriguez-Santiago, Head of Corrosion and Wear Branch at NAVAIR. Download Victor’s presentation
This presentation will combine “Development and Validation of a Cyclic Humidity Corrosion Test” (SERDP-ESTCP Symposium 2018) and “Galvanic Compatibility Assessment: New Methodology and Standardization” (ASETS Defense Workshop 2018).
- Jim Dante, Manager of Environmental Performance of Materials at Southwest Research Institute. Download Jim’s presentation
This presentation will summarize “Cyclic Corrosion and Failure Mechanisms” (SERDP-ESTCP Symposium 2018).
- Kristen Williams, Senior Materials Engineer at Boeing. Download Kristen’s presentation
This presentation will summarize “Degradation and Failure Mechanisms of Protective Coating Systems” (SERDP-ESTCP Symposium 2018).
- Alan Rose, CEO/Principal Engineer at Corrdesa LLC. Download Alan’s presentation
Presentation title, “Using simulation to understand the difference between corrosion in atmospheric environments and chamber tests”.
The galvanic potential tables people have been using for years often give the wrong answer. Now the U.S. Navy is taking a new approach and updating MIL-STD-889, the galvanic corrosion standard, replacing galvanic charts and tables with corrosion rate calculations. What does this mean for industry?
The Simcenter conference was very interesting, providing a great opportunity to learn more about the present software tools and also the trends in future development. One key takeaway for Corrdesa was the presentation on ‘Design Manager’ – this is a very powerful tool allowing easy setup of many simulations to more thoroughly explore the design space. So now we have changed out engineering workflow to think in more of a stochastic framework of many simulations and ranges of parameters instead of deterministic simulations of one scenario after the other. This approach really leverages the power of our computing cluster and provides much more optimum solutions to our clients.
Alan’s corrosion simulation presentation was received very well with many questions and follow-up meetings. Much of the Siemens Simcenter community were unaware of the existence of the electrochemical modules within CCM+ and in particular the advances made in corrosion prediction. The presentation is available below showing how the ‘1D’ approach of Corrdesa Corrosion Djinn can be leveraged to assess corrosion risks in materials selection and then further refinement made in more complex designs with the use of CCM+ employing the Corrdesa electrochemical database.
The demand for lightweight design and better fuel-efficiency in the aerospace industry has reflected a significant increase in usage of more lightweight materials
such as CFC (Carbon Fiber Composite), titanium and aluminum alloys. Combinations of these dissimilar materials are often dictated by structural requirements that need to be fulfilled in the design. In an aircraft, these disparate materials are usually mechanically joined using fasteners or structural adhesives. However, when CFC and aluminum are connected, galvanic corrosion may be induced in the presence of moisture, introducing an additional degradation mechanism.
Corrosion Djinn is easy-to-use software available on-line and as an ‘App’ for IoS and Android, that helps
engineers and designers make sound material choices in design and maintenance by predicting and
quantifying galvanic corrosion risk at material interfaces.
The present approach for considering galvanic incompatibilities is simplistic and static. It is simplistic in
that the only thing it takes into account is the galvanic potential difference between two adjacent materials.An estimate of the galvanic corrosion severity is usually based on some form of galvanic potential table,
as in MIL-STD-889. However, in mixed material assemblies it is the galvanic current that determines the
severity of corrosion, not the galvanic potential, and the two are not directly related.
Aircraft typically comprise multiple materials, each exhibiting unique electrochemical properties. When they are exposed to harsh marine and global environments, the difference in material properties can lead to severe galvanic corrosion, causing safety risks, costly repairs, and reduced readiness.
By connecting the Corrdesa electrochemical database with Siemens STAR-CCM+ we can now assess corrosion risk using 3D models – enabling us to continue tackling the huge and costly corrosion issues. View the video for more information: https://t.co/9U5uLOGaqi https://t.co/LHokstlzUm
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