DYMAT 2009
Volume 2, 2009
DYMAT 2009 - 9th International Conference on the Mechanical and Physical Behaviour of Materials under Dynamic Loading
Page(s) 1449 - 1455
Section Constitutive Modeling
Published online 15 September 2009
DYMAT 2009 (2009) 1449-1455
DOI: 10.1051/dymat/2009205

Instantaneous strain rate sensitivity of metastable austenitic stainless steel

M. Isakov1, V.-T. Kuokkala1 and R. Ruoppa2

1  Tampere University of Technology, Department of Materials Science, P.O.B. 589, 33101 Tampere, Finland
2  Tornio Research Centre, Outokumpu Tornio Works, 95490 Tornio, Finland

Published online: 15 September 2009

The dynamic behavior of metastable austenitic stainless steel EN 1.4318 was studied in uniaxial tension at low and high strain rates. Instantaneous strain rate sensitivity was evaluated with strain rate change tests. Tensile Hopkinson Split Bar apparatus was modified with a momentum trap bar to create a jump in the loading wave amplitude, which resulted in a rapid change in specimen strain rate at a chosen strain level. Results of this study show that instantaneous strain rate sensitivity remains positive although the strain rate sensitivity of strain hardening is negative due to adiabatic heating effects. Furthermore, tests carried out at elevated and reduced temperatures indicate a relation between instantaneous strain rate sensitivity and austenite stability.

© EDP Sciences 2009