Abstract
In order to improve fatigue strength of Al alloy welded joints, the effects of grinding on weld reinforcements and toe-peening on weld toe lines were investigated. Fatigue tests were carried out on three series of A5083 Al alloy butt welded joints and A7N01 Al alloy cruciform welded joints. Fatigue strength of the treated joints were compared with thatof as welded ones.
Following results were obtained;
(1) Toe grinding and reinforcement removal grinding increased the fatigue limits of the butt welded joints by 59% and 120%, respectively.
(2) The fatigue limit of the peened joints was about 80-120% higher than that of as welded joints.
(3) The fatigue strength of the joints, thermally stress relieved after peening, was equal to that of as welded joints.
(4) The effect of the fatigue strength improvement can be attributed to compressive residual stress generated by toe-peening.
