Seawater reverse osmosis (SWRO) desalination plants have been built across Australia to secure water resources. The construction and maintenance of desalination plants require a wide range of materials such as metals, alloys and composites. As the working environments in desalination plants are highly corrosive, corrosion in SWRO desalination plants poses significant problems and financial burden during the construction and operational phases in terms of costly materials selection and ongoing plant maintenance.
Develop smart materials and select the most appropriate that would lead to optimised design, reliability and durability of SWRO desalination plants. Better understand the corrosion performance of existing materials, components and structures. Develop monitoring protocols pertaining to corrosion for the screening of dedicated lower cost-maintenance materials, with life cycle extension, to maximise output and efficiency in the desalination industry.
Corrosion behaviours of existing materials and alternative materials for SWRO plants were examined. Carbon fibre reinforced plastic is stronger and more durable than currently applied glass fibre reinforced plastics and is recommended as a good material choice for desalination plants. High alloy steels corrode similar to duplex stainless steel, and nickel alloys were the most resistant to corrosion.
Heat tints produced during welding significantly affect the corrosion resistance of stainless steels. Currently used pickling solutions contain hydrofluoric acid are to remove the heat tints and repassivate weldments. This solution could be replaced by a chemically safer solution which is effective at removing the heat tint of weldments of austenitic stainless steel, duplex stainless steel and super duplex stainless steel and has similar passivation capabilities.
Surface alloying of low-cost stainless steels with chromium or molybdenum can offer some economical advantages and provide equal or superior corrosion resistance.
Further investigations of the precise mechanism and effectiveness of concentrating the pickling solution and its effects on passivating stainless steel weldments.
Total Value: $1,359,933 (cash and in-kind contributions)
Principal Investigator: Professor Maria Forsyth
Title: Smart materials for corrosion management
Length: 34 months
Personnel: 10 collaborators contributing 2.25 FTE
- 2015. Wyld, P. Understanding the Effects of Crevice and Galvanic Corrosion for Seawater Desalination Plants Management. Masters thesis, Deakin University.
- 2015. Xiong, J., et al. The Restoration of the Passivity of Stainless Steel Weldments in Pickling Solutions Observed Using Electrochemical and Surface Analytical Methods. Corrosion 71 (10):1248-1256.
- 2013. Xiong, J., et al. The corrosion behaviors of stainless steel weldments in sodium chloride solution observed using a novel electrochemical measurement approach. Desalination 327:39-45.
- 2013. 68th International Annual Conference. Orlando, USA.
- 2013. Membranes Desalination Conference. Brisbane, Australia.