Sand Erosion
The effect of sand abrasion in seawater has been investigated but is difficult to quantify. Sand loadings of less than 200ppm rarely damage good protective films on copper-nickel alloys. Very fine sand (<0.05 mm) loadings are tolerable up to about 1000ppm. Larger diameter sand particles tend to be increasingly abrasive to the film in the 200-1000ppm range. The 70-30 alloys have somewhat greater tolerance for sand. For sand loadings of 1000ppm and for larger particles of sands in the 200-1000ppm range, the 2% manganese, 2% iron, copper-30% nickel alloy, C 71640, has proven very resistant. In fact, the alloy was originally developed to combat sand erosion at Uskmouth Power Station in the UK.
Copper Nickel for Seawater Corrosion Resistance and Antifoulin
90-10 and 70-30 Copper-Nickel Alloys
Corrosion Resistance
The Importance of the Surface
General Corrosion Rates
Localised Corrosion
Velocity Effects
Sand Erosion
Galvanic Properties
Handling Sulfides
Ferrous sulfate treatment
Biofouling Resistance
Ease of Biofouling Removal
Reasons for Biofouling Resistance
Boat Hull Experience
Offshore Sheathing
Conclusions
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