OLI Studio: Corrosion Analyzer offers several unique features which comprise OLI aqueous corrosion simulation technology.
Polarization curves
Polarization curves generated by the OLI Studio: Corrosion Analyzer show partial anodic and cathodic processes, the mixed potential, the corrosion potential, and the net current density. On the left is a curve showing the chemistry of water and carbon dioxide in contact with carbon steel.
This technology is based on OLI's electrolyte thermodynamic model in combination with a kinetic model for generalized corrosion.
Real-solution Pourbaix diagrams, stability diagrams
OLI Studio: Corrosion Analyzer
Understanding the chemistry of the corrosion environment
Pourbaix diagrams are graphical depiction of EH vs. pH for any mixture of chemicals in water. They are used to evaluate stable and meta-stable corrosion and redox products. This allows assessment of the effect of passivating species in real solutions without any simplifying assumptions
Pourbaix's diagrams were created using ideal-solution theory; that is, Pourbaix assumed a water activity of 1. With OLI corrosion's technology, clients can create "real-solution" Stability Diagrams, taking the water activity and the ion-ion interactions into account. The result is the ability to define conditions for metal dissolution, passive films and surface deposits. This in turn can determine optimum pH, concentrations, and EH to minimize corrosion tendencies.
Stability diagrams permit flexible selection of independent variables and graphical depiction of local and global equilibria in various projection. Depictions include EH vs. composition and composition vs. pH for any chemical mixture, including trace components, to assess stable and metastable species in real solutions.
Yield diagrams are a graphical tool ito design the synthesis of compounds (e.g., ceramics) with desired yield for virtually any chemical mixture, including trace components.
Rates of chemical corrosion
General corrosion rates and corrosion potential can be mechanistically predicted for a large selection of alloys, including carbon steel, stainless steels, Ni-based alloys, Cu, Cu-Ni alloys, and aluminum. The predictions are based on an electrochemical model that incorporates surface reactions on the corroding metal in the active and passive state, adsorption of active species, active-passive transition and transport processes to and from the corroding interface. The rates are predicted by taking into account the possible cathodic and anodic processes on the surface and computing the corrosion potential and associated corrosion current density using the mixed potential theory.
Tendency for localized corrosion
The corrosion and repassivation potentials are calculated for the investigated alloy. In regions where the corrosion potential is larger than the repassivation potential, localized corrosion (pitting or crevice corrosion) can be expected. The maximum propagation rate of individual pits is also estimated.
Extreme value statistics (EVS)
Extreme Value Statistics predicts long-term propagation of localized corrosion on the basis of short-term or medium-term data. In particular, given samples of pit depth, EVS Analyzer calculates remaining asset life using a statistical model
