Failure Analysis And Residual Life Evaluation Of Deaerator Feedwater Storage Vessel Of Power Plants

The paper analyze the mechanics of deaerator feedwater storage vessel structure on the base of concluding the basic theories and the implement methods, some factors affecting to accurate results is discussed . The vessel structure effect to stress distribution is studied in detail by the ANSYS software. The diversified stress of vessel is computed colligating the Equivalent linear methods and Original structure method , the stress and the thinnest plate is proofread on ASME standard, That the influence of weld residual stress to the material mechanics performance and vessel stress varying with time is discussed.Distribution of steel metallographic structure,stiffness and the structure effect to the mechanical properties is analyzed. Initiative place of cracks and extend model ,structure configuration and stress distribution is discussed deeply by comparing the W structure and ferrite impacting toughness in heat affected zone. Water quality and scum of vessel is detected by Ion chromatogram and XPS respectively. Corrosion failure Manner and mechanism, the cause of crack is discussed comprehensively.The component tension (CT)fatigue crack growth experiment is implemented in term of vessel material structure and stress orientation , the fracture toughness is computed exactly by Levenberg-Marquardt arithmetic, and the fatigue life is evaluated by the Paris-Erdogan formula in term of fracture mechanics theories.