Microstructural changes in SAF 2507 superduplex stainless steel produced by thermal cycle

Abstract

This research work studies the microstructural changes in SAF 2507 superduplex stainless steel after thermal cycle in the range from 200 to 900°C for 20 minutes. The results showed there is no microstructural change in the temperature range of 200-700°C. However, over 800°C the sigma phase precipitates; the percentage of this phase increases with temperature. Sigma phase precipitates at the boundaries of δ/δ and δ/γ. The experimental results also showed precipitation of small particles of sigma phase at 900°C all over the microstructure showing the initial stages of formation.