Abstract The sensitivity of the fatigue limit of an additively manufactured, Ni-based superalloy 718 sample to surface finishing conditions and solute hydrogen was investigated via a series of tension–compression fatigue tests. The results revealed that neither defects nor hydrogen diminished the fatigue limit of the sample. The high defect tolerance of this material is attributed to a large unit of crack initiation in the coarse grain, which eclipses the detrimental effect of AM-process-induced defects. Also, from the results, it is inferred that hydrogen has little effect on the crack propagation rate and the crack growth threshold of the material.

中文翻译：

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一种增材制造的镍基高温合金 718 疲劳极限的缺陷容限和氢敏感性

摘要 通过一系列拉压疲劳试验研究了增材制造的 Ni 基高温合金 718 样品的疲劳极限对表面精加工条件和溶质氢的敏感性。结果表明，缺陷和氢都没有降低样品的疲劳极限。这种材料的高缺陷耐受性归因于粗晶粒中裂纹萌生的大单元，这掩盖了 AM 工艺引起的缺陷的不利影响。此外，从结果推断氢对材料的裂纹扩展速率和裂纹扩展阈值几乎没有影响。