After calculation of corrosion rate, a corrosion diagram is shown in Graph frame. The program chooses to display polarization curves or H₂S concentration profile depending on the dominant corrosion mechanism. The additional functionality to control the display of polarization curves is provided in Display Control frame.

Polarization Plot (Polarization Curves)

If corrosion process is electrochemical reaction dominant, the polarization curves, which relate potential with values of current density, are shown for each individual electrochemical reaction involved in the corrosion process. In addition, the total anodic and cathodic reaction as well as sweep polarization curve are also shown. Polarization curves are distinguished by different color of lines matching the color of corresponding captions of the names of polarization curves, as listed under the polarization plot. The total cathodic polarization curve is generated by summing up the polarization curves of all the cathodic reactions involved in the corrosion process. The same procedure applies to the total anodic polarization curve. Sweep curve is produced by subtracting total anodic curve from total cathodic curve.

In order to inspect individual reactions user can choose to show or hide each polarization curve at his/her convenience. This can be done by checking or unchecking the check boxes that are associated with the names of curves listed under the plot. Also, the font color of curve name is the same one as that in the diagram, which facilitates recognition of different curves. For instance, by unchecking H+reduction checkbox, the reaction curve ‘H⁺reduction’ will be not displayed in the diagram (see figure). It is important to mention that this operation does not interfere with corrosion calculation process and therefore does not change the final corrosion rate.



Concentration Profile (H₂S Concentration Profile)

When corrosion process is H₂S dominant, a plot which gives the concentration profile of H₂S through the layers existing on steel surface is shown (see figure). The y-axis gives the concentration of H₂S in ppm, and the x-axis gives the distance away from the steel surface in mm. Based on H₂S corrosion mechanism, four layers are present on steel surface, counting from the steel surface, they are inner makinatewite film, outer porous layer, and mass transfer boundary layer respectively.