Investigation of Crevice Corrosion Behavior of Aluminumand AISI۳۱۶ Stainless Steel in Nuclear Power Plant safetyimportant equipment and Introducing a PreventiveMethod

A well known crevice corrosion is of greatest concern for material which are normally passivemetals, like Stainless steel or Aluminum. Crevice corrosion tends to be of greatest significanceto component built of highly corrosion- resistant super alloy and operating with the pursetavailablewater chemistry. For example steam generator in nuclear power plant degrade largelyby crevice corrosion. Crevice corrosion is extremely dangerous because it is localized and canlead to component failure which the overall material loss is minimal. This work has beendevoted to the crevice corrosion and introduces a simple method to prevent that. In this method,attempt has been down to minimize the dead space that causes the crevice corrosion. Thecomparative capabilities of type AISI۳۱۶ stainless steel and aluminum were studied for usedin the processing nuclear power plant. The AISI۳۱۶ Stainless steel showed a considerablyhigher crevice corrosion resistance than Aluminum. As the concentration of H۲O-NaClsolution increases, the corrosion pace is also increased for both aluminum and steel for all typesof isolators. For any concentration, all three time intervals and both aluminum and stainlesssteel, the order of decrease in corrosion is: ۱. Grease, ۲. Glue, ۳. Gasket, ۴. Simple (withoutisolator). This indicates that as a matter of a fact by applying grease between parts whenattaching it is simply possible to prevent corrosion. The effect of grease and glue on crevicecorrosion control is similar but the effect of grease is more significant. The main cause for thisphenomenon goes back to the fact that grease (after it glue) fills the curves and holes on thesurface of both metals and does not leave behind any space or situation to trap solutions andtherefore crevice corrosion does not happen.

کلیدواژه ها:

Crevice Corrosion ، Prevention ، Stainless Steel ، Aluminum.