抄録
The purpose of the present investigation is to improve the fatigue strength of a non-load-carrying cruciform fillet welded joint by applying abrasive water jet kinetic energy to the weld toe region. FEM analysis, measurements of residual stress and hardness at toe region and 0-tension fatigue test of the fillet welded joint were performed for analyzing the improvement of fatigue strength. Fatigue failures invariably occurred at toe region. Main results obtained are summarized as follows:
(1) Fatigue limit of a water jet treated joint could be improved to about 1.6-2.0 times (180-224 MPa) that of a joint as-welded by suitable water jet treatment (LP-pass number: W07538, W05010, W10038-3, W07538-3, W10038).
(2) The reasons for such an improvement are considered to lie in tensile residual stress being decreased ; hardness increased ; and stress concentration decreased at toe region, depending upon the condition of water jet treatment.
