Stress Corrosion Cracking of Stainless Steel in Heavy Black Liquor - Mill Experience
Bibliographic record
Abstract
Abstract This paper describes the cracking failure of a UNS S30403 (304L) stainless steel 72% heavy black liquor storage tank at a Canadian bleached kraft pulp mill. The tank was installed in 1995 and operated reliably for 20 years when leaks were found in the upper part of the cylindrical shell. Samples of the cracked area were removed for laboratory examination. Investigation showed that the cracking initiated on the inside surface of the tank in the “tidal” zone where the liquor level fluctuates during normal operation of the mill. The laboratory investigation showed that the cracking was chloride stress corrosion cracking. This failure is consistent with findings at other mills in that high chloride was found in the crack tips even though the bulk chloride content of the liquor is much lower (of the order of 0.28 % on a dry solids basis which equates to 0.39% in the “liquid” 72% black liquor). Analysis of the organic residue on the corroded surface indicated that the organic species in the black liquor were oxidized in the tidal zone, and formed organic acids, which combined with the concentration effect allowed stress corrosion cracking to occur.
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 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 | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 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) | 0.002 | 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".