Corrosivity Evaluation of Copper-Nickel Alloy (90/10) in Pumps Used in Offshore Platforms for Seawater Pumping
This work discusses the case of corrosion in a copper-nickel alloy used in seawater, where chlorination is necessary to control micro- and macro-organism growth that can render inoperable the seawater supply system used in an offshore platform. Studies developed in the last 30 years have shown copper-nickel’s adequateness in seawater, with a corrosion rate of about 0.001mm/year. However, annual equipment inspection showed localized corrosion in an internal chamber in a stand-by pump. Such corrosion occurred due to high-concentration of sodium hypochlorite (NaClO) injection into the operational system, even for pumps that were out of operation. To evaluate this corrosive process, gravimetric (mass loss) and electrochemical tests were developed in synthetic seawater with NaClO at concentrations of 100, 500, 1000 and 5000mg/L. The results indicated that the corrosiveness varied from low to moderate. The presence of pitting and crevices observed in the laboratory tests derails or compromises material use in seawater. It was concluded that there is a need for continuous monitoring of the NaClO injection in seawater pumps, and a method was proposed in order to minimize or avoid a high concentration of chlorine in standby pumps.
C. Kapsalis, G. Schmitt, R. Feser, B. Sagebiel, S. Wilmes, M. Macziek, “New investigations on critical wall shear stresses of CuNi alloys in natural and artificial seawater”, Eurocorr - 2011, Stockholm, Sweden, September 4-8, 2011
W. Schleich, “Typical failures of CuNi 90/10 seawater tubing systems and how to avoid them”, Eurocorr - 2004, Nice, France, September 12-16, 2004
J. H. Michel, I. Richardson, C. Powell, B. Phull, “Development of copper alloys for seawater service from traditional application to state-of-the art engineering”, Corrosion 2017, New Orleans, USA, March 26-30, 2017
A. L. Ma, S. L. Jiang, Y. G. Zheng, W. Ke, “Corrosion product film formed on the 90/10 copper–nickel tube in natural seawater: composition/structure and formation mechanism”, Corrosion Science, Vol. 91, pp. 245-261, 2015
ASTM, ASTM G31-72, Standard Practice for Laboratory Immersion Corrosion Testing of Metals, ASTM International, 1999
NACE, NACE-RP0775-2005, Standard Recommended Practice: Preparation, Installation, Analysis, and Interpretation of Corrosion Coupons in Oilfield Operations, NACE, 2005
M. Pourbaix, “Licoes de Corrosao Eletroquimica”, in: Brasileira de Corrosao–ABRACO1, pp. 338-342, 1988 (in Portuguese)
F. J. Kievits, F. P. Ijsseling, “Research into the corrosion behavior of CuNi10Fe alloys in seawater”, Materials and Corrosion, Vol. 23, No. 12, pp. 1084–1096, 1972
A. H. Tuthill, “Guidelines for the use of copper alloys in seawater”, Materials Performance, Vol. 26, No. 9, pp. 12-22, 1987
H. H. Uhlig, Uhlig's Corrosion Handbook, John Wiley & Sons, 2011
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