Fracture Causes of Steel Bar of Drum Screen in a Nuclear Power Plant

Two broken steel bars of a drum screen in a domestic nuclear power plant were found during dailyinspection.The fracture reason of the steel bar was studied by means of metallographic analysis,scanning electronmicroscopy(SEM),and so on.The results indicated that the steel bar corroded in seawater.Under the tension andcompression loads produced by the rotation of the drum,corrosion fatigue fracture of the steel bar occured.