Research Of SCC Crack Growth Rate In Safety End Welded Joint Of Primary Circuit In Nuclear Power Plants

Mechanical heterogeneity of welded joint made the prediction of stress corrosioncracking (SCC) growth rate more difficulty which is a hot field in nuclear safety operationresearch field. The “sandwich”model is usually adopted in traditional simulation of weldedjoint, which existed mutations at the interface between materials. Based on micromeasurement of welded joint, the model accorded with actual welded joint was established byusing finite element software and compared with other models. The crack growth drivingforce parameter was studied. The main research works are performed as follows:(1) Using compact tensile (CT) samples as the research object. compared the crackgrowth driving force of homogeneous material model and the influence of materialparameter on crack growth driving force was analyzed in order to obtain aconservative material parameters to study the driving force on crack growth;(2) Using “sandwich”model, J integral and stress and strain at crack tip of differentlocation crack was calculated. The applicability of J integral was discussed for“sandwich”model of interface crack;(3) Material continuous model was established based on micro measurement of weldedjoint and the crack growth driving force of different crack location was calculated.Compared with other model, establishing a new method can be adopted for weldedjoint evaluating;(4) Strain rate was selected as the driving force and the SCC crack growth rate ofprimary circuit safety end in nuclear Power Structures was forecasted.This research provides a certain theoretical basis for SCC crack growth rate of weldedjoint and residual life calculation.