Abstract
Tensile creep behaviour of fine-grained Fe–Mn binary alloys containing 0.42–1.21 wt.% Mn has been investigated in the temperature range from room temperature to 475 K under 10–50 MPa. Tensile tests are carried out with a constant cross-head speed under uniaxial load at a strain rate 10−4s−1. Stress exponent and activation energy are determined to clarify deformation mechanism. The obtained variation of steady state creep rate with respect to the applied stress for Fe–Mn binary alloys exhibits two distinct regimes at about 20 MPa, indicating a possible change in creep mechanism. The average stress exponent is approximately 2.2, which is a characteristic of grain boundary sliding in the alloys. The activation energy for plastic flow varies from 135 to 92 kJ/mol, depending on the Mn content.