Long-term performance of epoxy-based coatings: Hydrothermal exposure
Notice bibliographique
Résumé
We examined the effects of prolonged exposure to high temperature water on epoxy-based powder barrier coatings applied to steel panels, which are commonly used in many industrial applications including oil & gas pipelines. The coatings' performance was evaluated over 85 weeks at 65 °C using deionized water. We also compared the mass transport properties of free-standing coating films with the barrier performance of the coated steel panels. This research lays the groundwork for predicting cumulative damage and time-dependent barrier performance of a priori pristine coating systems. Although these coating systems are intended for decades of in-service use, we found that some degradation effects caused by permeant sorption within the coatings can be detected as early as 8 weeks in the ageing process. Despite the coatings' barrier performance, substrate oxidation was readily observed after 182 days, as shown by cross-sectional and focused ion beam milling analysis. Colorimetry measurements of the underlying substrate, conducted after coating removal, also revealed that the first 200 days of exposure were critical for the development of underlying corrosion reactions. This period is characterized by the likely degradation of the epoxy network and the onset of a steady state in mass transport mechanisms. We also analyzed the adhesion strength of the coated panels over time. The epoxy-based coating's pull-off strength declines rapidly due to water-induced plasticization, but the adhesion properties of the epoxy network show a slight recovery due to secondary cross-linking by Type II bound water. This study underscores the complexity associated with predicting the time-to-failure for epoxy coating systems. However, the data and analyses provided herein offer valuable insights into the implications of extreme exposure conditions, aiding in the construction of lifetime predictions using a stochastic process. In real-world scenarios, pipelines undergo various fluctuations in parameters like temperature and humidity, potentially leading to failure. A deterministic physical/chemical model under simplified conditions can serve as input for the probability distribution function of future failure events. • The effects of long-term (500+ days) hydrothermal exposure on epoxy-coated steel are evaluated using a range of techniques. • Under-coating corrosion was detected after only 200 days of exposure. • EIS measurements revealed significant declines in low-frequency impedance with notable fluctuations over time. • Coating adhesive strength markedly declined (by up to 80 %) with exposure time. • FIB-SEM of aged samples revealed increased corrosion penetration and coating disbondment over time.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,004 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».