Understanding the weld-root-based fatigue failure of welded cast steel joints is critical, and the fatigue stress parameter corresponding to the S-N curve for the fatigue-derived design of welded cast steel joints still needs to be addressed. In this paper, we compared three widely used fatigue stress parameters, namely, the structural hot spot stress, the traction stress, and the 1-mm stress, for the analysis of different types of welded cast steel joints under various loading conditions. The results indicate that: (1) the structural hot spot stress calculated through linear extrapolation is close to the traction stress proposed by Dong (2001) but is easier to compute; (2) the 1-mm stress performs slightly better in correlating the fatigue data of different joint geometries and loading conditions, but its calculation requires more effort; and (3) finally, the equivalent hot spot stress parameter is proposed for fatigue design and data-based analysis of welded cast steel joints as it balances computational efficiency and data correction accuracy. Two S-N curves corresponding to the equivalent hot spot stress and the 1-mm stress are provided for the fatigue-based life evaluation of welded cast steel joints.

了解焊接铸钢接头的焊缝根部疲劳失效至关重要，而对于焊接铸钢接头的疲劳衍生设计，与SN曲线对应的疲劳应力参数仍有待解决。在本文中，我们比较了三种广泛使用的疲劳应力参数，即结构热点应力、牵引应力和 1-mm 应力，用于分析不同类型的焊接铸钢接头在各种载荷条件下。结果表明：（1）通过线性外推计算得到的结构热点应力与Dong（2001）提出的牵引应力接近，但更容易计算；(2) 1-mm 应力在关联不同接头几何形状和加载条件的疲劳数据方面表现稍好，但其计算需要更多工作；(3) 最后，提出等效热点应力参数，用于焊接铸钢接头的疲劳设计和基于数据的分析，以平衡计算效率和数据校正精度。提供了对应于等效热点应力和 1-mm 应力的两条 SN 曲线，用于焊接铸钢接头的疲劳寿命评估。