主催: 一般社団法人 日本機械学会
会議名: M&M2018 材料力学カンファレンス
開催日: 2018/12/22 - 2018/12/24
This study investigated fatigue crack propagation behavior and the number of cycles to fatigue crack arrest of cast Ni based superalloy 246 below its fatigue limit. Fatigue tests were performed under two-step variable amplitude stresses above and below the fatigue limit under load controlled condition. Low level stresses σLow below the fatigue limit are set as 91.4 MPa and 68.6 MPa. As the result of the observation of the micro cracks and they progresses under σLow = 91.4 MPa. Also in the case of σLow = 68.6 MPa, the micro crack progresses. In comparison between the number of cycles to stop fatigue crack propagation under σLow = 91.4 MPa and 68.6 MPa, the number of cycles under σLow = 68.6 MPa is less than σLow = 91.4 MPa.