TY - JOUR
T1 - Fatigue strength and fracture mode of superrapid induction hardened steel with shallow hardened layer
AU - Komotori, Jun
AU - Inoue, Fumi
AU - Kanda, Michiaki
AU - Shimizu, Masao
AU - Misaka, Yoshitaka
AU - Kawasaki, Kazuhiro
PY - 1997
Y1 - 1997
N2 - Four kinds of surface hardened specimens having hardened thicknesses of 0.7 approx. 1.8 mm were prepared using a 'Micropulse induction heating system'. Rotation bending fatigue tests were performed with special focus on the effect of hardened thickness on fatigue properties. Measurement of residual stress and observation of the fracture surface were also carried out to investigate the fracture mechanism of the specimen with a shallow hardened layer. It was found that there is not much improvement of fatigue strength at 107 cycles for specimens with shallow hardened layers in spite of having a high compressive residual stress of about 1 000 MPa. This is because the fatigue cracks originating from inside the hardened layer leads to final fracture of the specimen (internal fracture mode). Improvement of fatigue strength has been achieved by forming thick hardened layers. In this case, fatigue cracks originate from inclusions located in hardened layers, which leads to the final fracture (hardened layer fracture mode).
AB - Four kinds of surface hardened specimens having hardened thicknesses of 0.7 approx. 1.8 mm were prepared using a 'Micropulse induction heating system'. Rotation bending fatigue tests were performed with special focus on the effect of hardened thickness on fatigue properties. Measurement of residual stress and observation of the fracture surface were also carried out to investigate the fracture mechanism of the specimen with a shallow hardened layer. It was found that there is not much improvement of fatigue strength at 107 cycles for specimens with shallow hardened layers in spite of having a high compressive residual stress of about 1 000 MPa. This is because the fatigue cracks originating from inside the hardened layer leads to final fracture of the specimen (internal fracture mode). Improvement of fatigue strength has been achieved by forming thick hardened layers. In this case, fatigue cracks originate from inclusions located in hardened layers, which leads to the final fracture (hardened layer fracture mode).
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U2 - 10.1299/kikaia.63.240
DO - 10.1299/kikaia.63.240
M3 - Article
AN - SCOPUS:0031071233
SN - 0387-5008
VL - 63
SP - 240
EP - 245
JO - Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A
JF - Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A
IS - 606
ER -