高强度钢焊接接头疲劳强度

Fatigue strength of welded joints of high strength steel

采用单点试验法和小样子升降法相结合的试验方法,在应力比r=0.12下,对高强度钢的两种焊接接头进行了拉拉疲劳强度试验。并对焊接接头型式对疲劳寿命的影响进行了数理统计分析。试验结果和分析表明:对接接头的疲劳极限σ0.12为230MPa;角接接头的疲劳极限σ0.12为130MPa;同时得到了两种接头型式的S N曲线和P S N曲线方程。在应力水平250MPa、置信度95%条件下,对接接头的中值疲劳寿命是角接接头中值疲劳寿命的6～8倍。

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.