Anodic Characteristics of Copper, Wrought CuNi10, and CuAl10Ni5Fe4 in Seawater: Part 1—Polarizations Below 200 mV at Rotating Disc Electrodes and Rotating Cylinder Electrodes

• Published in: Corrosion (Houston, Tex.) Vol. 65; no. 1; pp. 24 - 36
• Main Authors: Kear, G, Barker, B D, Stokes, K R, Walsh, F C
• Format: Journal Article
• Language: English
• Published: Houston NACE International 01.01.2009
• Subjects: Aluminium; Aluminum; Aluminum bronzes; Anodic dissolution; Anodic polarization; Aqueous electrolytes; Charge transport; Chloride ions; Chlorides; Computational fluid dynamics; Copper; Corrosion; Corrosion potential; Cylinders; Diagnostic systems; Dichlorides; Diffusion theory; Dissolution; Dissolving; Electrode polarization; Electrodes; Electrolytes; Laminar flow; Mass transport; Nickel; Polarization; Rotating cylinders; Rotating disks; Rotation; Seawater; Turbulent flow
• ISSN: 0010-9312; 1938-159X
• DOI: 10.5006/1.3319111

The anodic, chloride ion-facilitated dissolution of copper, wrought 90-10 copper-nickel, and wrought nickel aluminum bronze, in controlled aqueous chloride electrolytes, has been examined at comparatively low values of polarization, i.e., <200 mV relative to the corrosion potential. Laminar flow to a rotating disc electrode (80 < ReRDE < 3,800) and turbulent flow around a rotating cylinder electrode (1,920 < ReRCE < 26,100) were considered at low values of anodic polarization. Using diagnostic factors that were previously developed for unalloyed copper, the dissolution characteristics of the materials have been compared in a systematic manner. A kinetic model, in conjunction with convective-diffusion theory, has been applied to describe the general behavior of all three materials. The chloride ion facilitated a relatively rapid rate of dissolution via cuprous dichloride ion formation, and each system showed mixed (charge and mass transport) control of the anodic dissolution.