Analysis and control of welding deformation for CFETR vacuum vessel PS2

摘要

The large scaled vacuum vessel (VV) of CFETR is designed as a water-cooled, double-walled structure with a D-shaped poloidal cross-section. One sub-sector of VV contains four poloidal segments (PS) assembled by welding. Because of the large size of the VV, the distortion caused by welding will make the assembling difficult. Controlling the deformation during the welding process is a significant technological challenge. This article gives the analysis of the deformation of the component during the welding process, the optimization of the welding process and the design of the welding tooling and clamping positions firstly. Based on the inherent strain theory, the welding deformation analysis of the five different welding sequences of PS2 is performed, and the corresponding welding tooling and clamping positions are designed in accordance with the deformation results. The methods provide highly valuable information for the actual processing, and the welding deformation of PS2 in the actual production has been well controlled, all of which are within the tolerance requirements.