The dynamic compressive behavior and constitutive modeling of D1 railway wheel steel over a wide range of strain rates and temperatures

The dynamic compressive behavior of D1 railway wheel steel at high strain rates was investigated using a split Hopkinson pressure bar (SHPB) apparatus. Three types of specimens, which were derived from the different positions (i.e., the rim, web and hub) of a railway wheel, were tested over a wide range of strain rates from 10(-3) s(-1) to 2.4 x 10(3) s(-1) and temperatures from 213 K to 973 K. Influences of the strain rate and temperature on flow stress were discussed, and rate- and temperature-dependent constitutive relationships were assessed by the Cowper-Symonds model, Johnson-Cook model and a physically-based model, respectively. The experimental results show that the compressive true stress versus true strain response of D1 wheel steel is strain rate- dependent, and the strain hardening rate during the plastic flow stage decreases with the elevation of strain rate. Besides, the D1 wheel steel displays obvious temperature-dependence, and the third-type strain aging (3rd SA) is occurred at the temperature region of 673-973 K at a strain rate of similar to 1500 s(-1). Comparisons of experimental results with theoretical predictions indicate that the physically-based model has a better prediction capability for the 3rd SA characteristic of the tested D1 wheel steel. (C) 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license