Effect of Preaging Deformation on Aging Characteristics of 2507 Super Duplex Stainless Steel

In the present study, precipitation of sigma (r) phase was investigated over the temperature range of 700-850 degrees C in undeformed and deformed (60% cold rolling) samples of 2507 super duplex stainless steel. The fraction of sigma phase formed as a result of the transformation alpha -> sigma + gamma(2) increases with increasing time and temperature. The increase in sigma phase leads to increase in yield strength and decrease in ductility. Preaging deformation leads to accelerated precipitation of sigma phase. The activation energy for sigma phase precipitation in deformed sample is found to be lower than that in undeformed sample