Development of a Nano-Composite Coating Technology for Improvement of Carbon Steel Pipe to Erosion-Corrosion in Oil Sands Slurry

Erosion-corrosion (E-C) has constituted an essential threat to the integrity of oil sands slurry hydrotransport system. To improve the resistance of carbon steel pipes to E-C in oil sands slurry, a composite coating technology has been developed by electrolytic deposition in this research. Parametric effects on the structure and properties of the coating were investigated in order to fabricate high performance coatings. It is found that the electrodepositing parameters, such as the concentration of SiC nano-particles in bath electrolyte, cathodic current density, current pattern and temperature, affect remarkably the particle deposition which relates directly with the coating performance. Furthermore, the parameters in pulse current electrodeposition also affect the properties and performance of the prepared coatings. Enhancements of the corrosion resistance and micro-hardness of the coating have been obtained at a low duty cycle and high frequency, which result in an increased amount of SiC particles in the coating. The nucleation and early stage growth mechanism of the composite coating on the steel substrate was determined by cyclic voltammetry, chronoamperometry current transient measurements and atomic force microscopy (AFM) characterization. A mixed instantaneous and progressive mechanism is followed during electrodeposition under low cathodic overpotentials. At high overpotentials, it switches to the instantaneous mechanism. An empirical model based on the modified Guglielmi’s model was developed to enable quantification and prediction of the co-depositing rate of SiC particles with Ni-Co coating during pulse electrodeposition. To understand the E-C behavior of pipe steel in oil sands slurry and the performance of the fabricated coating for E-C resistance, parametric effects, including the sand concentration, flow velocity and impact angle, on the E–C behavior of bare and coated steels were studied. It is demonstrated that erosion components are the dominant contributors to E–C in oil sands slurry, while the contribution of corrosion components is slight. The developed Ni-Co-SiC nano-composite coating shows a higher resistance to E-C than the base steel.

Name thesis:degree_name

Doctor of Philosophy (PhD)

Discipline thesis:degree_discipline

Mechanical and Manufacturing Engineering

Grantor dc:publisher.institution

Graduate Studies

Year dc:date.issued

2013

Author dc:creator

• Yang, Yang

Advisor dc:contributor.advisor

• Cheng, Yufeng (Frank)

• Materials Science
• Mechanical

Statement dc:rights

• University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.

Language dc:language.iso

eng

DOI

http://dx.doi.org/10.11575/PRISM/25663

OAI identifier oai:identifier

oai:ucalgary.scholaris.ca:11023/949