The article deals with the development of advanced techniques of low cycle fatigue testing (LCF) using miniature test samples, which has the potential to be used to assess the degree of material degradation of large in-service components in the power industry. For this purpose, the results of a wide portfolio of test samples geometries have been investigated. Using the advanced techniques involving a special sampling device, a DIC virtual extensometer and test rig, a new possibility in strain-controlled LCF testing is presented. The results indicated that cyclic-strain and strain-life curves of proposed minisample geometries are almost of the same shape for both investigated rotor steels. Also the cyclic parameters obtained indicate a good consistency of results despite of a wide range of sample volumes and utilization of two different strain-control methods.

本文介绍了使用微型测试样品开发低周疲劳测试 (LCF) 的先进技术，该技术有可能用于评估电力行业中大型在用部件的材料退化程度。为此，研究了广泛的测试样品几何结构组合的结果。使用涉及特殊采样装置、DIC 虚拟引伸计和试验台的先进技术，提出了应变控制 LCF 测试的新可能性。结果表明，对于所研究的两种转子钢，所提出的微型样品几何形状的循环应变和应变寿命曲线几乎具有相同的形状。