The release of stored energy during recovery and recrystallization of coldrolled ultra high purity iron

Plastically deformed samples of ultra high purity iron (UHP) doped with 150 ppm of niobium were investigated by differential temperature scanning calo rimetry (DTSC) determining the stored energy and the activation enthalpy of recovery and recrystallization. Any oxidation effects were successfully pr evented with a newly constructed device for cleaning the specimens by ion-e tching and enclosing them hermetically in noble metal capsules without any contact to air. Compared with pure iron the stored energy and the activatio n enthalpy are increased in the Fe-Nb alloy resulting in a large shift of t he recrystallization temperature.