CORROSION RATE MEASUREMENT OF GALVANISED FIRE SERVICES IN DRINKING EATER

摘要

The corrosion rate of galvanised steel has been experimentally measured in the laboratory principle using linear polarisation resistance techniques. The results obtained are verifiable in terms of solution analysis. The work has shown that conditions of aeration are more significant than the source and composition of the water. In general, the following general corrosion rates apply: 1.Deaerated waters: 0.5-1 micron per year. Aerated unstirred water: 15 microns per year. Stirred water: 10-40 microns per year. Carbon dioxide satuated and stirred water: 150-200 microns per year. The sample sets of necessity restricted in size and some systems (eg aerated unstirred) would need additional work to establish repro-ducibility of results. Moreover, the influence of primary physical constants such as pH and alkalinity has not been established. Nevertheless, these results form a basis for establishing conditions under which galvanised steel fire services operate and can be used in conjunction with the longer-term test rigs currently operating at OneSteel.