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Investigation of corrosion rates with an electrochemical measuring cell in relation to the W 0 ‐factor according to DIN 50929‐3 and the concentration of dissolved organic carbon (DOC)
Author(s) -
Ruppert J.,
Frimmel F. H.,
Baier R.,
Baumann H.
Publication year - 2017
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.201609163
Subject(s) - immersion (mathematics) , corrosion , dissolved organic carbon , chloride , chemistry , electrochemistry , sulfate , humic acid , analytical chemistry (journal) , inorganic chemistry , environmental chemistry , materials science , metallurgy , electrode , mathematics , pure mathematics , fertilizer , organic chemistry
The W 0 ‐factor is a common metric to express the aggressivity of water against unalloyed iron. It accounts for multiple parameters, called rating numbers, which represent the concentration of chloride, sulfate and calcium ions, the pH‐value and the acid capacity of the immersion medium. The use of ranges in the physical quantities metric rating number, however, allows for unaccounted variations in the immersion medium composition, i.e., slightly different immersion media may produce the same W 0 ‐factor. To verify the results, the experiments were also carried out with natural waters as immersion media and their W 0 ‐factors were determined. In addition, the DOC content, which is not included in the W 0 ‐factor, has an impact on the corrosive character of the immersion medium. In order to account for the influence of the DOC content in the measurements, multiple solutions with different DOC concentrations were investigated. The results show that a higher DOC content (based on humic substances) in the observed solutions causes a reduction in the corrosion rate. This result agrees with observations of nature.