MIL-STD-889D Revised Standard for Assessing Galvanic Corrosion
With the release of MIL-STD-889D the requirements for assessing galvanic corrosion risk in defense systems has changed radically. The new standard was just released and it transforms the way we assess galvanic corrosion risk.
Until now the title of the standard was simply ‘Dissimilar Metals’. The title on the newly-released MIL-STD-889D is “Galvanic Compatibility of Electrically Conductive Materials”, reflecting the fact that it covers materials of all types, such as composites, gap fillers, conductive gaskets, sealants, coatings, and even in some cases treatments – Al 2024 bare, chromate converted, trivalent passivated, etc.
The Galvanic Table is gone. The standard completely changes the whole methodology used to determine galvanic compatibility. You can no longer just look up where a particular material or coating falls on the Galvanic Series, or lump it with similar materials. Even measuring its galvanic potential is not enough. The new standard is based on correctly predicting the corrosion rate between any pair of materials, using electrochemical mixed potential theory (a.k.a polarization curve crossing). This makes it necessary to use the polarization curves of all the galvanically-coupled materials in an assembly to predict corrosion rates.
In the webinar we will present and discuss the challenges in implementing a consistent corrosion analysis capability across enterprises. We will introduce a workflow that incorporates a quick galvanic corrosion calculation using the Corrosion Djinn® software, developed from our DoD work and fully compliant with MIL-STD-889D. Additionally we will show how full 3-dimensional, deeper dive corrosion analyses can be conducted using the Siemens Teamcenter® and multi-physics software CCM+ combined with the Corrdesa electrochemical database to predict corrosion rate maps over 3D CAD components. This process will be demonstrated with examples of computational corrosion analysis on F/A-18 components.