No abstract

Corrosion in underground and submerged steel pipes is a global problem. Coatings serve as an impermeable barrier or a sacrificial element to the transport of corrosive fluids. When this barrier fails, corrosion in the metal initiates. There is a critical need for sensors at the metal/coating interface as an early alert system. Current options utilize metal sensors, leading to accelerating corrosion. In this paper, a non-conductive sensor textile as a viable solution was investigated. For this purpose, non-woven Zinc (II) Oxide-Polyvinylidene Fluoride (ZnO-PVDF) nanocomposite fiber textiles were prepared in a range of weight fractions (1%, 3%, and 5% ZnO) and placed at the coating/steel interface. The properties of ZnO-PVDF nanocomposite meshes were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and d33 meter. Electrochemical impedance spectroscopy (EIS) testing was performed during the immersion of the coated samples to validate the effectiveness of the sensor textile. The results offer a new option for sub-surface corrosion sensing using low cost, easily fabricated sensor textiles.

No abstract

Nanocrystalline zinc titanate (ZnTiO3) coatings were deposited by atomic layer deposition (ALD) on AISI 52100 steel to study ZnTiO3 corrosion protection. The main aim of this study was to determine how the coating can inhibit pitting formation of 52100 steel in both saline solution and simulated body fluid (SBF) media. Potentiodynamic polarization tests revealed increasing corrosion potentials for the ALD ZnTiO3-coated steel specimens with protective efficiencies of 83 and 73% in saline solution and SBF, respectively. Atomic force microscopy analysis of both the ZnTiO3-coated and uncoated steel revealed a high surface potential value for the ZnTiO3-coated sample as compared to the uncoated sample with a relatively low surface potential. The corrosion rates for the coated steels in both media were calculated and observed to drop by an order of magnitude. Due to the conformality, homogeneity and density of the ALD ZnTiO3 coatings, migration of Cl− and OH− ions from the electrolytes were inhibited resulting in the improved corrosion resistance.