13th International Conference on Fracture June 16–21, 2013, Beijing, China -4- 100 200 300 400 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Tangential force coefficient, φ Stress amplitude, σa (MPa) Solution heat-treated SUS304 f = 20Hz pc = 100MPa Buffing Uncharged In air In H2 (b) Increase in tangential force coefficient Figure 3. Adhesion between contacting surfaces during fretting fatigue test in hydrogen Cut Resin Observation Adhered specimen and pad Figure 4. Observation of adhered part at the longitudinal section of the adhered specimen and pad (SUS304, σa = 180MPa, N = 1.0×10 6). typically found in a specimen because no fatigue stress is applied to the contact pad. The morphology of the small fretting fatigue cracks in hydrogen was unique compared to that observed in air. If a contact pad is simply placed on the specimen without fretting, the boundary of the specimen and pad should be a straight line. However, at positions A, B and C, the interface was not (a) Adhered specimen and contact pad (SUS316L, uncharged, σa = 200MPa, Nf = 5.4×10 5 )
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