TY - JOUR
T1 - Resistance to mechanically small fatigue crack growth in ultrafine grained interstitial-free steel fabricated by accumulative roll-bonding
AU - Lin, X.
AU - Koyama, M.
AU - Gao, S.
AU - Tsuji, N.
AU - Tsuzaki, K.
AU - Noguchi, H.
N1 - Funding Information:
This work was financially supported by JSPS KAKENHI ( JP16H06365 ) and Elements Strategy Initiative for Structural Materials (ESISM) of Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan .
Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2019/1
Y1 - 2019/1
N2 - Effects of ultrafine grain refinement on fatigue crack growth were investigated using an interstitial-free (IF) steel with a grain size of 590 nm produced by accumulative roll bonding. The fatigue properties and associated microstructures were characterized by fully reversed bending fatigue tests, replica method coupled with optical microscopy, and electron backscattering diffraction measurements near the fracture surfaces. Compared with a coarse-grained IF steel tested at the same stress amplitude, the fatigue strength of ultrafine-grained steel was higher, which was attributed to an increase in hardness. Compared with the coarse-grained steel at the same ratio of stress amplitude to hardness, the crack growth rates in the ultrafine grained steel were higher in the short-crack regime because of the smaller crack roughness and perhaps the difference in the strain gradient at the crack tip.
AB - Effects of ultrafine grain refinement on fatigue crack growth were investigated using an interstitial-free (IF) steel with a grain size of 590 nm produced by accumulative roll bonding. The fatigue properties and associated microstructures were characterized by fully reversed bending fatigue tests, replica method coupled with optical microscopy, and electron backscattering diffraction measurements near the fracture surfaces. Compared with a coarse-grained IF steel tested at the same stress amplitude, the fatigue strength of ultrafine-grained steel was higher, which was attributed to an increase in hardness. Compared with the coarse-grained steel at the same ratio of stress amplitude to hardness, the crack growth rates in the ultrafine grained steel were higher in the short-crack regime because of the smaller crack roughness and perhaps the difference in the strain gradient at the crack tip.
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U2 - 10.1016/j.ijfatigue.2018.09.002
DO - 10.1016/j.ijfatigue.2018.09.002
M3 - Article
AN - SCOPUS:85053762820
SN - 0142-1123
VL - 118
SP - 117
EP - 125
JO - International Journal of Fatigue
JF - International Journal of Fatigue
ER -