双相不锈钢焊接接头疲劳评定体积法

Fatigue assessment of duplex stainless steel welded joints by volumetric approach

摘要: 应用体积法对SAF2205双相不锈钢两种不同形式的焊接接头疲劳强度进行了评定研究,对该方法的适用性和有限元计算过程影响因素进行了分析讨论。结果表明,对焊态焊接接头,体积法局部平均应力Δσ_ave|^Ω参量为具有一定普遍意义的疲劳控制参量,对于讨论的两种接头,由Δσ_ave|^Ω表示的焊接接头疲劳强度与接头形式无关;对SAF2205双相不锈钢两种不同形式焊接接头,其局部疲劳强度Δσ_ave|^Ω=411.3 MPa;采用体积法进行疲劳评定时,为得到合理的评定结果,应选取最小单元尺寸e_min≤0.14 mm进行计算。上述结果为简化焊接接头疲劳评定提供重要依据。

Abstract: The volumetric approach (VA) was applied to the fatigue assessment of SAF2205 duplex stainless steel welded joints with two types of geometrical modes, and its feasibility and the effect of the finite element calculation on this method were discussed. It was shown that VA local average stress is an universal fatigue restraining parameter, and the fatigue intension expressed by the local average stress is independent of the joint geometries. For the welded joints, the local average stress is 411.3 MPa, and the reasonable predicting results can be obtained if the local parameters are calculated by selecting the minimal element size which is 0.14 mm or lower. The results offer the important gist for predigesting the fatigue assessment of welded joints.