日常检查时发现某核电厂鼓型旋转滤网有两根斜拉筋在螺纹处发生断裂,对失效拉筋断口宏观形貌、微观形貌、材料成分、力学性能、金相、拉筋受力等进行了分析。结果表明,拉筋受到海水腐蚀,在鼓网旋转过程中产生的拉压载荷作用下,拉筋发生了腐蚀疲劳断裂。

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.