Continuous Dynamic Recrystallization and Grain Refinement of AISI 430 Ferritic Stainless Steel

초록

The softening mechanism of AISI 430 ferritic stainless steel was studied by torsion tests. The deformation tests were performed in the temperature range of 900 - 1100℃ and strain rate range of 5.0x10-2 - 5.0x100/sec. The evolutions of flow stress and microstructure show the characteristics of continuous dynamic recrystallization (CDRX). The flow stress gradually decreased with strain over the peak stress without steady state. Within the 100% effective strain, the grains appeared small angle grain boundaries from EBSD analysis. On the other hand, the larger deformation over the 300% was applied, the higher misorientation was achieved. The tendency of CDRX was increased with increasing strain rate and decreasing temperature.