Real-Time Early Warning Strategies for Corrosion Mitigation in Harsh Environments

• Type: Article in International Scientific Journal
• Date: 2018

Authors

Costa Coelho, LCC (Author) FCUP; Soares dos Santos, PSS (Author) Other; Jorge, PAS (Author) FCUP; Santos, JL (Author) FCUP; de Almeida, JMMM (Author) FCUP

Journal

Title: Journal of Lightwave Technology

Vol. 36

Pages: 1152-1158

ISSN: 0733-8724

Publisher: Optical Society of America

Indexing

ISI Web of Knowledge - 4 Citations

Scopus - 7 Citations

Other information

Authenticus ID: P-00N-9YS

DOI: 10.1109/jlt.2017.2755076

Abstract (EN): Long period fiber gratings (LPFGs) were coated with iron (Fe) and exposed to oxidation in air and in water having different concentrations of sodium chloride (NaCl) to detect the formation of iron oxides and hydroxides. The process was monitored in real time by measuring the characteristics of the LPFGs attenuation bands. Thin films of Fe were deposited on top of silica (SiO2) substrates, annealed in air, and exposed to water with NaCl. The composition of the oxide and hydroxide layers was analyzed by SEM/EDS and X-ray diffraction. It observed the formation of oxide phases, Fe3O4 (magnetite), and Fe2O3 (hematite) when annealing in air, and Fe-2(OH)(3) Cl (hibbingite) and FeO(OH) (lepidocrocite) when exposed to water with NaCl. Results shows that Fe-coated LPFGs can be used as sensors for real-time monitoring of corrosion in offshore and in coastal projects where metal structures made of iron alloys are in contact with sea or brackish water. In addition, LPFGs coated with hematite were characterized for sensing, leading to the conclusion that the sensitivity to the refractive index of the surrounding medium can be tuned by proper choice of hematite thickness.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7