Investigation of strain-rate sensitivity of T91 Steel Using Small Punch Testing

The Small Punch Test (SPT) is a useful technique for deriving location-dependent mechanical properties using small-sized specimens. In this work, we have investigated the tensile and fracture behavior of T91 steel, a candidate material for fusion and Gen IV fission nuclear reactors, by the SPT technique. Firstly, the hot shear flow behavior of T91 steel was investigated by SPT in the temperature range of 400 – 550 °C under quasi-static strain rates (0.003 mm/min and 0.3 mm/min). Further, the hot deformation material parameters in the exponential power-law and hyperbolic sine constitutive equations have been evaluated. The effect of temperature and strain rate variation on stress exponent in power-law and activation energy from hyperbolic sine equation have been correlated.