Fatigue strength of welded joints of high strength steel

With one-point experiment and the minimum of sepcimens expriment,the fatigue tests on butt and angle welded joints of high strength steel were carried out when its stress ration is 0.12. The effects of butt and angle welded joints on the fatigue life were analyzed with mathematical statistics.The results indicated that the fatigue limit(σ_0.12)) of butt welded joints is 230 MPa and the fatigue limit(σ_0.12)) of angle welded joints is 130 MPa. The fatigue curve of S-N and P-S-N were achieved.The fatigue life of butt welded joints is 6～18 times as long as that of angle welded joints under conditions of 250 MPa stress level and 95% reliability.