Plastic deformation of delta-ferritic iron at intermediate strain rates

The plastic deformation of delta-ferritic iron, represented by an electrolytic iron and Fe-0.028 C, Fe-0.044 C and Fe-3.0 Si alloys, has been measured for the temperature range 1200 to 1525‡C and the strain rate range 2.8 x 10^-5 to 2.3 x 10^-2 s^-1. For the bamboo-like tension specimens the plastic flow behavior is approximately nonlinear viscous. Delta-ferrite is more than four times weaker than austenite, and does not exhibit dynamic recrystallization. At the melting point of iron the extrapolated steady-state flow stress increases from 0.31 to 1.86 MN/m² (45 to 370 psi) over the range of strain rate examined.