TY - GEN
T1 - The influence of strain rate and strain on the behavior of stress relaxation in 980 MPa-grade dual phase steel sheets
AU - Murasawa, Kodai
AU - Komine, Hayato
AU - Otake, Yoshie
AU - Sunaga, Hideyuki
AU - Takamura, Masato
AU - Ikeda, Yoshimasa
AU - Suzuki, Shinsuke
N1 - Publisher Copyright:
© 2016 Trans Tech Publications, Switzerland.
PY - 2016
Y1 - 2016
N2 - The specimens (980 MPa-grade dual phase steel sheets) were stretched until the pre-defined strain was obtained. Then the specimens were held at the pre-defined strain and measured the change of stress during holding. We investigated the effects of strain rate and strain at the starting time of holding and whether the stress change during holding could be described by Krempl model. The following results were obtained. First, the stress drop increased with increase of strain rate and the holding time. On the other hand, the stress drop was not affected by strain change at the starting time of holding. Second, initial stress relaxation rate increased with increase of strain rate. However, this strain rate dependency to stress relaxation rate diminished as the holding time became long enough roughly more than 100 s. Third, the stress change during holding obtained by Krempl model accurately agreed with experimental result. It was found that the stress change during holding could be well described by using Krempl model. This suggests that dislocation moves viscously. In addition, the strain rate dependency on stress change during holding could be described by change of the parameter A.
AB - The specimens (980 MPa-grade dual phase steel sheets) were stretched until the pre-defined strain was obtained. Then the specimens were held at the pre-defined strain and measured the change of stress during holding. We investigated the effects of strain rate and strain at the starting time of holding and whether the stress change during holding could be described by Krempl model. The following results were obtained. First, the stress drop increased with increase of strain rate and the holding time. On the other hand, the stress drop was not affected by strain change at the starting time of holding. Second, initial stress relaxation rate increased with increase of strain rate. However, this strain rate dependency to stress relaxation rate diminished as the holding time became long enough roughly more than 100 s. Third, the stress change during holding obtained by Krempl model accurately agreed with experimental result. It was found that the stress change during holding could be well described by using Krempl model. This suggests that dislocation moves viscously. In addition, the strain rate dependency on stress change during holding could be described by change of the parameter A.
KW - High-Strength Steel Sheet
KW - Stress Relaxation
KW - Stress-strain Relationship
KW - Viscoelasticity
KW - Viscoplasticity
UR - http://www.scopus.com/inward/record.url?scp=84992695475&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84992695475&partnerID=8YFLogxK
U2 - 10.4028/www.scientific.net/KEM.716.948
DO - 10.4028/www.scientific.net/KEM.716.948
M3 - Conference contribution
AN - SCOPUS:84992695475
SN - 9783038357049
T3 - Key Engineering Materials
SP - 948
EP - 953
BT - Metal Forming 2016
A2 - Szeliga, Danuta
A2 - Muszka, Krzysztof
PB - Trans Tech Publications Ltd
T2 - 16th Metal Forming International Conference, 2016
Y2 - 18 September 2016 through 21 September 2016
ER -