Effect of cold rolling reduction on texture, recrystallization and mechanical properties of UNS S32304 Lean Duplex stainless steel

The effect of cold rolling reduction on the texture, extended recovery, recrystallization and mechanical properties of UNS S32304 Lean Duplex stainless steel was investigated. EBSD analysis showed that alpha '-martensite transformation in austenite phase caused a shear band formation in ferrite phase. An austenite grain with {110}<112> Brass component transformed to alpha'-martensite with {001}<110> rotated cubic component was found according to the Kurdjumov-Sachs (K-S) orientation relationship after 63% cold rolling reduction. Evidence that extended recovery and discontinuous recrystallization occurred in the ferrite phase was observed. The increase in cold rolling reduction caused an increase in the softened fraction and the fraction of grains with GOS<1 degrees mainly due to the extended recovery in the center. The increase in cold rolling reduction causes higher stored energy and affects the discontinuous recrystallization in the austenite phase. On the other hand, the austenite texture was not influenced and a decrease in its intensity was only observed during annealing. The uniform elongation and total elongation remained approximately constant after the softened fraction reached 0.92 and the complete recrystallization of austenite phase.

Automated summary

The study found that cold rolling reduction has a significant effect on the microstructure and mechanical properties of UNS S32304 Lean Duplex stainless steel, especially on the transformation to α'-martensite and the extended recovery and recrystallization processes.