Hot working and micro structure in 409 ferritic steel

After continuous casting, homogenization and hot working, 409 ferritic stainless steel was deformed by torsion to different strains up to fracture. At 800–1000 °C flow curves exhibited clearly defined peaks followed by gradual softening which was greater at higher stresses. At 600 °C with ge = 0.01 s−1, deformation curves show only strengthening to failure but a peak is present at 700 °C. At 900–1000 °C, flow curves approach a steady state. The optical microstructure at 600 °C consists of deformed grains with little recovery. At 700–1000 °C, elongated grains contain substructure which is more developed at higher T and ε and lower ge with no evidence of dynamic recrystallization.