Abstract The influence of creep damage on high cycle fatigue (HCF) in Alloy 617M at 973 K was investigated in the present study by devising a novel method of incorporating periodic hold at the alternating stress/maximum stress. Under such HCF-creep interaction tests, the endurance limit was found to shift downwards compared to that obtained under HCF cycling. The modified endurance limit was found to be a strong function of HCF block size as well as the hold-time employed. This leads to modification of S-N curve, evolving scopes of re-evaluating the HCF design rules. The test data was further utilized to generate a HCF-creep interaction diagram. The knee-point which marks the allowable damage was found to be lower when a lower block-size is employed, indicating a strong block-size dependency of such diagram. The influence of creep on HCF cycling was also corroborated with fracture surface investigations showing significant intergranular cracking during such tests.

中文翻译：

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在 973 K 下生成 617M 合金中的 HCF-蠕变相互作用图

摘要 本研究通过设计一种在交变应力/最大应力下结合周期性保持的新方法，研究了蠕变损伤对 973 K 合金 617M 高周疲劳 (HCF) 的影响。在这种 HCF-蠕变相互作用测试中，与 HCF 循环下获得的相比，发现耐久极限向下移动。发现修改后的耐久极限是 HCF 块大小以及所用保持时间的强函数。这导致 SN 曲线的修改，演变重新评估 HCF 设计规则的范围。测试数据进一步用于生成 HCF-蠕变相互作用图。当使用较小的块大小时，发现标记允许损坏的拐点较低，表明此类图具有很强的块大小依赖性。