Corrosion Characteristics of Mild Steel in Urea Ammonium Nitrate Fertilizer Solutions
Bibliographic record
Abstract
Anodic polarization studies have been conducted on mild steel in urea ammonium nitrate (UAN) fertilizer solutions comprising 31 wt% urea ([NH2]2CO), 39 wt% ammonium nitrate (NH4NO3), and 30 wt% H2O, with a total N content of 28 wt% (UAN 28-0-0). It was determined that mild steel can spontaneously exhibit either active-passive or passive behavior when immersed in UAN solutions. At 23°C, specimens exhibiting active-passive behavior experienced corrosion rates of ~2 mm/y for pH values in the range of 3 to 8.5. At pH values <3, the corrosion rate increased rapidly, reaching a value of 92 mm/y at a pH of 1.1. Specimens exhibiting passive behavior experienced corrosion rates of ~0.002 mm/y for the pH range of 6 to 8.5. An increase in temperature from 23°C to 60°C increased the corrosion rate of specimens exhibiting active-passive behavior from ~2 mm/y to ~15 mm/y. To minimize corrosion, mild steel storage tanks for liquid UAN fertilizer should be kept free of sludges and other contaminants, which could provide stagnant areas where low pH areas can develop. Further, storage tanks should be painted a light color since darkly painted tanks experience higher temperatures and thus higher corrosion rates.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".