Structural Steels. Influence of Induction Hardening Conditions on Torsional Fatigue Strength of Induction-Hardened Shafts with Hole Notches
構造用鋼 円孔切欠き材のねじり疲労強度に及ぼす高周波焼入れ条件の影響

Yasushi Matsumura, Yutaka Kurebayashi, Sadayuki Nakamura
Synopsis The effect of induction-hardened depth on torsional fatigue of hole notched specimens was investigated. The results are as follows. 1 Induction-hardened specimens show the best torsional fatigue strength when the effective case depth / radius ratio is about 0.5. 2 In the case of shallow case depth, the cracks initiate at the hardened / non-hardened boundary. On the other hand, the fracture of deeply hardened specimen originates at the surface layer. 3 The cracks initiate at the hole
more » ... face in the normal direction of principal stress, because the principal shear stress is smaller than principal stress at hole surface.
doi:10.4262/denkiseiko.69.17 fatcat:g4uteea2bjf3jibwlxej5hb6o4