A mechanistic study of iron passivation and transpassive behavior in sulfate solutions using thermo-kinetic diagrams
Bibliographic record
Abstract
Understanding the dissolution and passivation of iron in aqueous environments is essential for enhancing its corrosion resistance and expanding its applications. We present Thermo-Kinetic (TK) diagrams for iron in deaerated solutions with no added sodium sulfate (Na 2 SO 4 ) and with 0.1 M Na 2 SO 4 over the pH range 1–14, constructed by integrating current density contours from potentiodynamic polarization with thermodynamic E-pH diagrams. TK diagrams indicate that in solutions with no added Na 2 SO 4 , iron passivates above pH 7, with a minimum passive current density (i p ) of 5 ×10 −6 mA·cm −2 at pH 8. The addition of 0.1 M Na 2 SO 4 delayed passivation until pH 12 and increased i p nearly tenfold. Galvanostatic (GS) polarization and EIS validated the TK diagram results. XPS after GS polarization revealed an FeOOH/Fe 2 O 3 film at pH 10, while Fe 3 O 4 /Fe 2 O 3 dominated at pH 12 and 14. These results clarify how sulfate compromises iron passivity and highlight TK diagrams as a powerful tool for mapping corrosion behavior.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".