Issue34

Y. Nakai et alii, Frattura ed Integrità Strutturale, 34 (2014) 246-254; DOI: 10.3221/IGF-ESIS.34.26 252 Rolling direction (A) (B) (C) Contact surface x y z x z y Inclusions ■ Crack x y z x z y (A) (B) (C) ■ Crack x y z x z y (A) (B) (C) x y z x z y (A) (B) (C) ■ Crack x y z x z y (A) (B) (C) ■ Flaking (a) N = 6.00 × 10 6 cycles (b) N = 6.80 × 10 6 cycles (c) N = 7.10 × 10 6 cycles (d) N = 7.50 × 10 6 cycles (e) N f = 7.67 × 10 6 cycles ■ Crack 50 m  50 m  50 m  50 m  50 m  (A) x y z (C) (B) Rolling direction Contact ball Observation direction Figure 9 : 3D-images of cracks and inclusions.