Study on Distribution and Optimization of Residual Stress inside Plate-Fin Structure after Braze Welding

The residual stress inside the plate-fin structure has been analyzed by the finite element method under different operation conditions.The calculated results show that a large scale of residual stress will occur in the plate-fin structure and the maximum value is found at the braze corner.The rapid cooling process and the pressured assembly technology have a significant effect on the distribution of the residual stress.The brazed material owns a better performance with a quicker cooling rate.However,the quicker cooling rate also leads to a tensile residual stress near the brazed seam,which is deleterious to the whole structure.The pressure assembly technology can change the residual stress from a tensile state to the compressed state which can improve the safety and extend the service life of the plate-fin structure effectively.