Is there Intergranular Stress Corrosion Cracking (IGSCC) in Fossil Fuel Power Plants at Condensers?
Copper alloy condenser tubes, particularly brass condenser tubes, are susceptible to condensate corrosion in steam condensate that contains high concentrations of NH3 and oxigen. Consequently, condensate corrosion, like SCC, is most prevalent in the air removal section. Condensate corrosion, also know as NH3 attack, is form of corrosion in the metal but by the localization of the corrosive enviromnet. For example, the slight tilt routinely give to condenser tubes may promote flow of some of the steam condensate toward one side of a tube support plate. There, the flow from a large number of tubes can collect and run down the plate surface. Such localized flow can create deep surface. Such localized flow can create deep circumferential grooves, termed condensate grooving, in the tubes immediately next to the support plate if the condensate contains high levels of NH3 and by reducing the oxigen concentration in the condensate, as discussed previously for stemm-side SCC or by selecting mor
