TY - JOUR
T1 - Strain rate and hydrogen effects on crack growth from a notch in a Fe-high-Mn steel containing 1.1 wt% solute carbon
AU - Najam, Hina
AU - Koyama, Motomichi
AU - Bal, Burak
AU - Akiyama, Eiji
AU - Tsuzaki, Kaneaki
N1 - Funding Information:
This work was financially supported by the Japan Science and Technology Agency (JST) (grant number: 20100113 ) under the Industry-Academia Collaborative R&D Program and JSPS KAKENHI ( JP16H06365 and JP17H04956 ). B. Bal acknowledges the Scientific and Technological Research Council of Turkey (TÜBİTAK, Project No: 118M448).
Publisher Copyright:
© 2019 Hydrogen Energy Publications LLC
PY - 2020/1/1
Y1 - 2020/1/1
N2 - Effects of strain rate and hydrogen on crack propagation from a notch were investigated using a Fe-33Mn-1.1C steel by tension tests conducted at a cross head displacement speeds of 10−2 and 10−4 mm/s. Decreasing cross head displacement speed reduced the elongation by promoting intergranular crack initiation at the notch tip, whereas the crack propagation path was unaffected by the strain rate. Intergranular cracking in the studied steel was mainly caused by plasticity-driven mechanism of dynamic strain aging (DSA) and plasticity-driven damage along grain boundaries. With the introduction of hydrogen, decrease in yield strength due to cracking at the notch tip before yielding as well as reduction in elongation were observed. Coexistence of several hydrogen embrittlement mechanisms, such as hydrogen enhanced decohesion (HEDE) and hydrogen enhanced localized plasticity (HELP) were observed at and further away from the notch tip resulting in hydrogen assisted intergranular fracture and cracking which was the key reason behind the ductility reduction.
AB - Effects of strain rate and hydrogen on crack propagation from a notch were investigated using a Fe-33Mn-1.1C steel by tension tests conducted at a cross head displacement speeds of 10−2 and 10−4 mm/s. Decreasing cross head displacement speed reduced the elongation by promoting intergranular crack initiation at the notch tip, whereas the crack propagation path was unaffected by the strain rate. Intergranular cracking in the studied steel was mainly caused by plasticity-driven mechanism of dynamic strain aging (DSA) and plasticity-driven damage along grain boundaries. With the introduction of hydrogen, decrease in yield strength due to cracking at the notch tip before yielding as well as reduction in elongation were observed. Coexistence of several hydrogen embrittlement mechanisms, such as hydrogen enhanced decohesion (HEDE) and hydrogen enhanced localized plasticity (HELP) were observed at and further away from the notch tip resulting in hydrogen assisted intergranular fracture and cracking which was the key reason behind the ductility reduction.
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U2 - 10.1016/j.ijhydene.2019.10.227
DO - 10.1016/j.ijhydene.2019.10.227
M3 - Article
AN - SCOPUS:85075884193
SN - 0360-3199
VL - 45
SP - 1125
EP - 1139
JO - International Journal of Hydrogen Energy
JF - International Journal of Hydrogen Energy
IS - 1
ER -
