低変態温度溶接材料を用いた圧縮残留応力導入の為の溶接施工手順の提案

抄録

To understand the cause of compressive residual stress in welded joints, we analyzed by numerical analysis the effect of welding pass sequence using Low Transformation Temperature (LTT) welding materials, on residual stress around the weld toe of boxing fillet welded joints.
It was determined by numerical analysis that the produced compressive residual stress and the influence of the stiffeners are reduced in the equivalent position of the weld toe in a fillet welded joint because of the influence on behavior of the stiffener in the weld being due to residual stress distribution around the weld toe.
The residual stress reduction method of extending the length of the welded bead and releasing the weld toe from the stiffener, similar to the concept of discarding a bead to reduce tensile residual stress, was effective in fillet welded joints.
Numerical analysis of the relationship between residual stress around the weld toe and width of the weld bead in the bead-on-plate welding model, clarified that compressive residual stress can be introduced around the weld toe by having a wide width weld bead. In addition, a fully penetrated welded joint was very effective for causing compressive residual stress around the weld toe.