Regular Article

Strain rate sensitivity and strain hardening response of DP1000 dual phase steel

¹ Gazi University, Faculty of Technology, Department of Manufacturing Engineering, Ankara, Turkey
² Niğde Ömer Halisdemir University, Faculty of Engineering, Department of Mechanical Engineering, Niğde, Turkey
³ Gazi University, Faculty of Technology, Department of Metallugical and Materials Engineering, Ankara, Turkey

^* e-mail: onurcavusoglu@gazi.edu.tr

Received: 12 October 2017
Accepted: 30 January 2018

Abstract

In this study, strain hardening and strain rate sensitivity behavior of commercial DP1000 dual phase steel have been examined in detail at temperatures of 25 °C, 100 °C, 200 °C and 300 °C, at strain rates of 0.0016 s⁻¹ and 0.16 s⁻¹. As the strain rate has increased, the yield strength has increased but no significant change in tensile strength and strain hardening coefficient has been observed. As the temperature has increased, the yield and tensile strength has decreased in between 25 and 200 °C but it has showed an increase at 300 °C. The strain hardening coefficient has increased in parallel with temperature increase. It has been seen that the strain rate sensitivity has not been affected by temperature. No significant difference in the hardening rate has appeared in between 25 and 200 °C, but the highest value has been calculated at 300 °C. It has been determined that the fracture behavior has occurred earlier and load carrying capacity on necking has reduced with the increase of strain rate and not significantly affected by temperature.