Numerical Study on Welding Deformation of Upper Support Structure in 600MW Sodium-Cooled Fast Reactor

Abstract

The upper support structure of 600 MW sodium-cooled fast reactor is welded by inner and outer cylinders, upper and lower tube-sheets and multiple rib plates. The structure has a large size and many welding passes, which poses a great challenge to the control of welding deformation. It is an effective method to control welding deformation of structural parts by using numerical simulation method to predict welding deformation and optimize welding process. In this work, the welding process of typical T-joint is numerically simulated and tested firstly. The reliability of the simulated results is verified by comparing the temperature field, and the inherent strain of typical joint is obtained. Then, the inherent strain method is used to calculate the welding deformation of typical T-joint. The welding deformation accuracy is compared and analyzed by using thermoelastic-plastic method and inherent strain method, respectively. Finally, the welding process of the upper support structure is simulated by the inherent strain method. The influence of the designed welding sequence on the welding deformation of the upper support structure is studied, and the shrinkage allowance are obtained. The research results have been verified by field application, which provides technical support for the construction of 600 MW sodium-cooled fast reactor.