ABSTRACT
Copper occurs naturally in lean sulfide or oxide ore bodies in association with iron and sometimes also with nickel and the extraction processes by which it is recovered are expensive. The chemistry of copper and hence its corrosion behaviour is determined by its position as the penultimate element in the first transition series. Artefacts of copper and simple alloys surviving from antiquity, for example as ornaments, tools and coinage, testify to the excellent corrosion resistance of the metal in natural environments such as atmosphere, natural waters, soils, and water supply and circulation systems. It is difficult to find firm evidence for failure by stress-corrosion cracking or corrosion fatigue for pure copper, because the metal is ductile and applications for which it is exploited do not often impose high stresses. The constitutions of copper alloys are complex and detailed consideration of phase equilibria, system by system, is required to explain the effects of compositions on corrosion behaviour and corrosion resistance.
