Modelling the Brittle-Ductile Transition Temperature of Irradiated A508-3 Steel With CPFEM

Crystal Plasticity Finite Element Model (CPFEM) is the powerful tool to bridge the meso-scale and marco-scale and study the mechanical properties of metals systematically. In this paper, crystal plasticity theory coupling with irradiation effect is proposed. Note that it is based on density of dislocation and irradiation-induced full-absorption and partial-absorption dislocation loop and their interaction between each other. Then the model is numerically implemented in UMAT on ABAQUS platform. Secondly, A508-3 steel, the typical BCC crystal material, has specific brittle-ductile transition. The cleavage failure probability theory model (CFPTM) which assumes that the failure probability of specimen depends on its Cauthy stress filed is presented. The tensile tests for A508-3 steel are simulated by CPFEM in a combination of CFPTM to obtain the brittle-ductile transition temperature (BDTT). Results show that failure probability for specimen increases with increasing strain and decreasing temperature. In terms of BDTT, the numerical and experimental result are in close agreement whether there is under irradiation condition or not. Furthermore, the obvious irradiation embrittlement phenomenon is observed.