Intermediate-Temperature Heat Treatment of UNS N10003 Alloy during Cold Working

To explore an appropriate intermediate temperature of heat treatment during the cold working of UNS N10003 alloy, the influence of heat treatment temperature, time, the induced deformation, the mechanical properties, and microstructures by the pre-stretching method was investigated systematically. The results showed that after heat treatment (performed at 760 °C, 6 h), the strength was not reduced, and the elongation was not improved efficiently. However, after only 30 min of heat treatment at 870 °C, their strength was efficiently reduced, and their elongation was substantially improved, reaching the original sample level. Moreover, no apparent changes were observed with the extension of heat treatment time. The morphology of the microstructures and fractures indicated that the recovery and recrystallization process occurred at the temperature of 870 °C during the heat treatment, which resulted in the residual stress relieving and microstructural reconstruction. Correspondingly, the fractographs were also transformed from cleavage to ductile. Therefore, the heat treatment during the cold working should be carried out at 870 °C, enhancing energy- and cost-efficient production of UNS N10003 alloy.