Research of weld residual stress analysis technology of CRDM adapter

Background: Several aspects will influence the weld residual stress analysis of CRDM penetration, such as formation and distribution of heat source, heating and cooling processing, finite elements meshing, phase changing, etc. Purpose: Develop an effective method for weld residual stress analysis, research the influence of interval between heating and cooling step during multipass beads procedure. Methods: Finite elements with a sequentially coupled approach are applied, including a transient thermal analysis simulating the heating and cooling and their interval between multipass welding. Results: An appropriate finite method is developed for weld residual stress simulation. Conclusions: Appropriate interval time must be chosen between multipass weld beads to avoid poor weld residual stress, and contact pressure between RPV shell and CRDM adapter tube also should be check for structure integrity. (authors)