Dynamic tension studies of strength and formability characteristics of a high alloyed steel with respect to thermal activation

Essential properties of materials are characterized by strength and ductility. These to a large degree depend on loading conditions determined by temperatur and strain rate. An interdependence between contemporary changes in temperature and strain rate with respect to the yield point can be approached via the thermal activation theory. However, it is not known up to which strain rates the above theory is applicable with regard to high strength steels. Therefore the yield strength behaviour was investigated at high rates of strain especially from a high strength steel X 45 CrSi 9 3 in a quenced and tempered state. The obtained results prove that the Arrhenius-equation may be use to predict the yield strength up to strain rates of 10 E4 for this steel. In extension the Arrhenius-equation can also be used for the estimation of UTS when adiabatic heating is taken into account. For stress measurements, it is possible to lower the strain rates by using lower temperatures, thus avoiding a dif ficult testing procedure. In the case of deformation behaviour no rule of correlation between strain rate and temperature can be stated. (IFAM)