Evolution of residual stresses in 2205 DSS cruciform weld joints of filter press under water jet peening impact

Due to its excellent symmetry and superior mechanical performance, the cruciform welding joint is widely employed in various pressure equipment such as filter presses. The residual stress distribution in cruciform welded joints is complicated due to the variability in the number and sequence of weld passes, with significant stress concentration phenomena induced by geometric discontinuities, thereby impacting the structural durability of the joints. As a clean surface treatment technique, water jet peening (WJP) can effectively reduce surface residual stresses and improve surface performance, particularly suited for reinforcing the inaccessible welded joints. The cruciform weld joints contain four welds. The residual stresses be redistributed after each treatment on each weld. Improper WJP processes may affects the reduction effect of residual stresses of cruciform welded joints. In this paper, the evolution of residual stresses of 2205 Duplex Stainless Steel cruciform welded joints under WJP was investigated using numerical simulation and experiment. The mechanism of variation in residual stress distribution under different impact sequences were discussed. The results indicate that surface residual stresses in all four welds are effectively reduced by WJP. Among the different treatments, diagonal surface treatment (DST) demonstrates superior reduction in surface stress levels and overall stress distribution compared to single-sided treatment (SST) and sequential surface treatment (SeqST) and alternating surface treatment (AST) methods. The processing results of SeqST and AST exhibit minimal disparity. Considering both treatment effectiveness and cost, DST should be prioritized for engineering applications. This study provides valuable engineering guidance for the practical application of WJP in cruciform welded joint.