TY - JOUR
T1 - Roles of hydrogen content and pre-strain on damage evolution of TRIP-aided bainitic ferrite steel
AU - Verma, Virendra Kumar
AU - Koyama, Motomichi
AU - Kumai, Bakuya
AU - Hojo, Tomohiko
AU - Akiyama, Eiji
N1 - Funding Information:
This work was financially supported by JSPS KAKENHI (JP16H06365, JP18K04743, and JP20H02457).
Publisher Copyright:
© 2021 The Iron and Steel Institute of Japan.
PY - 2021
Y1 - 2021
N2 - From the aspect of crack/void initiation and growth characteristics, the effects of pre-strain on the hydrogen embrittlement resistance of a transformation-induced plasticity-aided bainitic ferrite steel were examined. The hydrogen uptake in the specimens without pre-strain caused degradation of crack growth resistance, but the crack initiation probability did not change significantly. It is noteworthy that the degree of degradation was independent of the hydrogen content in the present hydrogen charging condition. Pre-straining to 3% and 6% improved the crack growth resistance of the hydrogen-charged specimens because of a reduction in the probability of austenite presence at the crack tip. Furthermore, a high level of pre-strain provided high hydrogen concentration and resulted in strain-age-hardening, which caused an acceleration of quasi-cleavage fracture, an increase in yield strength, and a stress/strain concentration associated with Lüders deformation. These factors diminished the crack initiation resistance and crack growth resistance.
AB - From the aspect of crack/void initiation and growth characteristics, the effects of pre-strain on the hydrogen embrittlement resistance of a transformation-induced plasticity-aided bainitic ferrite steel were examined. The hydrogen uptake in the specimens without pre-strain caused degradation of crack growth resistance, but the crack initiation probability did not change significantly. It is noteworthy that the degree of degradation was independent of the hydrogen content in the present hydrogen charging condition. Pre-straining to 3% and 6% improved the crack growth resistance of the hydrogen-charged specimens because of a reduction in the probability of austenite presence at the crack tip. Furthermore, a high level of pre-strain provided high hydrogen concentration and resulted in strain-age-hardening, which caused an acceleration of quasi-cleavage fracture, an increase in yield strength, and a stress/strain concentration associated with Lüders deformation. These factors diminished the crack initiation resistance and crack growth resistance.
KW - Bainitic ferrite
KW - Hydrogen embrittlement
KW - Pre-strain
KW - Strain aging
KW - Transformation-induced plasticity
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U2 - 10.2355/isijinternational.ISIJINT-2020-514
DO - 10.2355/isijinternational.ISIJINT-2020-514
M3 - Article
AN - SCOPUS:85105093661
VL - 61
SP - 1309
EP - 1314
JO - Transactions of the Iron and Steel Institute of Japan
JF - Transactions of the Iron and Steel Institute of Japan
SN - 0915-1559
IS - 4
ER -