In this article, we show that quantification of pitting corrosion (steel samples) is simplified with infinite focus microcopy (IFM). Groups of terms obtained from optical survey can be combined to determine the percentage of corrosion. A new rapid method was developed to use computer image analysis to build a correlation that can quantify pitting characteristics, patterns and potential risks. This new fast calculation method saves time when studying samples of microbial influenced corrosion and the resulting pits.
Desulfovibrio vulgaris was used as a model sulfate reducing bacteria growing on carbon steel. The bacteria was challenged with a carbon limited condition to induce pitt formation, as the bacteria uses electrons donated from the steel substrate. Modeling was used to create and identify correlations between “real world parameters” and “IFM calculated values” (Sv, SK, Sdr, Vvv, Svk).
1. Maximum pit depth was linearly correlated with Sv + Sk
2. Average pit depth was correlate with Sdr/Vvv
3. Pitted area correlated with Svk·Vvv/Sdr
4. A 4-phase diagram of average pit depth vs pitted area percentage indicated pitting progression
Read the full article in the journal CORROSION