Investigating crevice corrosion of copper and copper alloys using wire beam electrode

ABSTRACT

A wire beam electrode (WBE) method for investigating the crevice corrosion has been demonstrated by mapping non-uniform corrosion processes occurring on copper and copper alloys including the pure copper UNS No. C11000 (Cu), brass UNS No. C28000 (Cu–Zn alloy) and tin bronze UNS No. C51900 (Cu–Sn alloy) in mass 0.6% NaCl solution with the crevice spacings of d=103 μm and 206 μm. It was found that the sequence of three copper alloys in susceptibility for the crevice corrosion was that Cu–Zn alloy > Cu–Sn alloy > pure Cu. The average galvanic current of the Cu–Sn alloy in the covered region was changed from cathode to anode when the crevice spacing was increased to 206 μm. To sum up, it is feasible to study the behaviours of crevice corrosion within the different crevice spacings with the WBE method.

KEYWORDS:

• crevice corrosion
• non-uniform corrosion
• crevice spacing
• WBE

Acknowledgements

The authors gratefully acknowledge State Key Laboratory of Advanced Special Steel, Shanghai University.