Damage and dynamic strain aging in a thermal aged cast duplex stainless steel

An experimental study was carried out at 320 °C in order to determine the damage kinetics of a thermal aged duplex stainless steel. Compression and tensile tests were performed at 320 °C and at 20 °C for comparison. Typical steps of damage for this material were found at room temperature. At 320 °C, no bulk damage was observed, but strain and damage were localized. The experimental mechanical results revealed the existence of dynamic strain aging. The absence of bulk damage is linked to this phenomenon: as soon as damage appears in ferrite, there is localization and fracture follows.