Dislocation microstructures in fatigued Fe–30 Mn–10 Al–0.4 C alloy

The dislocation microstructures developed in the austenitic phase of the duplex Fe–30 Mn–10 Al–0.4 C alloy after cycling at various total strain amplitudes are examined by transmission electron microscopy. Following solution treatment and quenching, the austenitic phase immediately undergoes spinodal decomposition. For total strain amplitudes less than 0.6%, it is found that the substructures consist of paired dislocations associated with the shearing of K‐phase carbide particles. Thus planar slip is a dominant deformation mode in the austenitic phase of the duplex alloy. However, there is a greater tendency for cell structure to form in the austenitic phase as the total strain amplitude increases to 1%. On further cycling of the alloy at a 2% strain amplitude, the dislocation cell structure predominates. Copyright © 1990 WILEY‐VCH Verlag GmbH & Co. KGaA