CORROSION OF COPPER IN AUSTRALASIAN DRINKING WATERS: A HISTORICAL REVIEW

摘要

Corrosion of copper drinking water pipes in Australasia was first reported in the literature from Auckland, New Zealand in the early 1970's. This unusual type of corrosion, not described elsewhere in the literature at that time, was called "blue water' due to the gross contamination of water by copper salts. This type of corrosion was then observed across the eastern seaboard of Australia in the mid to late 1970's, principally in Newcastle, NSW and later in Melbourne. Significant work by the CSIRO and others over decades showed that this type of corrosion is largely due to microbiological influenced corrosion (MIC) and improvements in water buffering and disinfection have largely solved the problem in municipal drinking waters. Concurrent with "blue water' was pitting corrosion in copper pipes, again largely restricted to cold, soft waters on the eastern seaboard of Australia and dezincification of brass fittings leading to blockage from corrosion products. Whilst the copper pitting issues were largely solved through the same remedial actions as with "blue water', dezincification was only prevented through metallurgical changes to the composition and heat treatment of the copper alloy material itself. More recently, both hot water pitting and corrosion/erosion in hot water recirculating systems have manifested themselves due to the high temperatures and velocities commonly used in Australia; these issues are ongoing.