Fracture Toughness Prediction Of Domestic A508-â…¢ Steel Based On Master Curve Approach And Its Application To Reactor Pressure Vessel P-T Curve

Most nuclear reactor pressure vessels are made of ferritic low-alloy steel, which exhibits a strong transition in fracture mode from ductile tearing to cleavage fracture. The mechanical properties of such material will be degraded under intense neutron irradiation, which will lead to the increase of the ductile-brittle transition temperature. It is likely that the reactor pressure vessel will operate in the ductile-brittle transition temperature range when an accident happens. Therefore, it's very important to accurately predict the variation in the fracture toughness data of reactor pressure vessel steel in the ductile-brittle transition temperature range, for ensuring the safety assessment and operation of reactor vessels. In this study, the newly developed Master Curve approach was applied to the research of domestic A508-Ⅲsteel fracture toughness and the reactor pressure vessel pressure-temperature limit curve.In this paper, tensile test, charpy impact test and fracture toughness test of domestic A508-III steel were carried out. Fracture toughness test temperature T was estimated through the correlation with charpy characteristic temperature. Respectively using of multi-temperature analysis and the single-temperature analysis, the master curve reference temperature To of 0.5T SE(B) specimens and 10×10mm PCVN specimens were determined. And the master curve of domestic A508-III Steel and facture toughness distribution in ductile-brittle transition temperature range were obtained. Considering the irradiation embrittlement of the material, the master curve was adjusted to predict the reactor pressure vessel pressure-temperature curve, and a case study analysis was given.