Continuous dynamic recrystallization of AISI 430 ferritic stainless steel by hot torsion deformation

The high temperature deformation behavior of AISI 430 ferritic stainless steel has been studied over a temperature range of 800 to 1000 degrees C and strain rate of 0.05-5.0/sec. The evolution of flow stress and microstructures showed the characteristics of continuous dynamic recrystallization (CDRX). The flow stress curves gradually decreased with increasing strain over the peak stress until 500% of strain without any steady state shown in typical austenitic stainless steel. Sub-grains of low angle firstly formed along the original high angle grain boundary were propagated into the inside of original grain and transformed to high angle. The CDRX grain sizes of AISI 430 deformed at 1000 degrees C and 0.5/sec was about 30-35 mu m.