CREVICE CORROSION IN SWRO PLANTS1 Saleh A.

Crevice corrosion is one of the major problems in SWRO plants. Crevice corrosion is one of the several types of localized corrosion responsible for many failures in the plants. It is caused by the difference in concentrations of oxygen, chloride ion, hydrogen ion and metal ions between solution inside crevice area and outside solution resulting in the formation of aeration or concentration cells. Many types of alloys have been used to construct the high pressure section of SWRO plant and these alloys are subjected to crevice corrosion. A number of alloys are developed to resist this type of corrosion. In this paper, the effect of alloy addition to steels, in order to improve their crevice corrosion resistance and mechanical properties, has been discussed. A survey of alloys used in SWRO plant and evaluation of these alloy vis-a-vis to the factors responsible for causing crevice corrosion have been carried out. Also, this paper discusses the results of several studies carried out to investigate the crevice corrosion of some conventional and high alloy stainless steels under different conditions and the possibility of using these alloys in SWRO