Impact Toughness of an Isothermally Treated Zeron®100 SDSS

The aim of the present study is to investigate the impact toughness of a UNS 32760 SDSS, in relation to the quantity of secondary phases precipitated after isothermal aging in the range of 850-950 °C and for different exposure times. The impact toughness has been investigated by means of instrumented impact testing, using Charpy V-notched specimens at room temperature. The impact testing results show that, for an amount of about 0.5% volume fraction of intermetallic phase, the impact toughness is reduced by over 50%. For volume fractions higher than 1.5-2%, the impact toughness is definitively compromised, and small entities of plastic deformations are enough to cause a prevailing brittle fracture mechanism. By increasing the precipitates’ amounts, the fracture mechanism shows an ever more prominent brittle behavior until 6% volume fraction, exceeding which the ductile component is totally absent.