Field and laboratory studies to evaluate the influence of Wet&Dry atmospheric depositions on weathering steel

Nobili, Lara (2018) Field and laboratory studies to evaluate the influence of Wet&Dry atmospheric depositions on weathering steel, [Dissertation thesis], Alma Mater Studiorum Università di Bologna. Dottorato di ricerca in Chimica, 30 Ciclo. DOI 10.6092/unibo/amsdottorato/8616.
Documenti full-text disponibili:
[img]
Anteprima
Documento PDF (English) - Richiede un lettore di PDF come Xpdf o Adobe Acrobat Reader
Disponibile con Licenza: Creative Commons Attribution Non-commercial No Derivatives (CC BY-NC-ND 3.0) .
Download (16MB) | Anteprima

Abstract

In this work, an innovative perspective was applied to study the effect that atmospheric depositions have on material corrosion. The influence of different atmospheric conditions on corrosion process was investigated using weathering steel (WS) both in natural exposures and laboratory tests. Specifically, the influence that different start time of material exposure and consequently different atmospheric conditions could have on the early stage of corrosion was evaluated by means of WS field exposures in terms of colour measurements, surfaces characterization, ions amount contained in the patina and corrosion rates. To achieve the maximum information and highlight possible correlations, all the significant variables were processed by Principal Component Analysis (PCA). Additionally, by means of the application of Design of Experiment as chemometric tool, laboratory tests (alternate immersion accelerated ageing tests) were performed on WS to evaluate the interaction among particulate matter inorganic anions and to investigate in more realistic conditions the influence of different amounts and proportions of chlorides, sulphates and nitrates on corrosion rate and metal release, underlining also competitive and synergic interactions between them. As well, through this approach it was possible to directly relate and predict the trend of the measured response factors within an experimental domain that represents different atmospheric compositions and build models that take into account also possible changes in the concentration of pollutants of growing interest. Lastly, in order to further investigate the action of particulate matter on different kind of materials and on differently oriented surfaces, a new developed device (called “Deposition Box”) to sample dry deposition was tested and validated through SEM/EDS analysis combined with the freeware software ImageJ. “Deposition Box” allows achieving reproducible samples of particulate matter (PM) dry deposits and to sample also fine particles (0.4 – 5 μm2) making the study of dry deposits less tricky.

Abstract
Tipologia del documento
Tesi di dottorato
Autore
Nobili, Lara
Supervisore
Co-supervisore
Dottorato di ricerca
Ciclo
30
Coordinatore
Settore disciplinare
Settore concorsuale
Parole chiave
Atmospheric Corrosion of Weathering Steel; Design of Experiment; Metal Release; Corrosion Rates; Particulate Matter; Accelerated Ageing Tests; Field Exposures
URN:NBN
DOI
10.6092/unibo/amsdottorato/8616
Data di discussione
17 Aprile 2018
URI

Altri metadati

Statistica sui download

Gestione del documento: Visualizza la tesi

^