The intrinsic stacking-fault energy of a fcc Fe-20Mn-4Cr-0.5%C alloy was measured at 100 to 390K using observations of dislocation nodes by transmission electron microscopy and shear modulus determination. The node size decreased continuously as the temperature increased. This variation was reversible below 300K and was largely irreversible above. The irreversibility was attributed to carbon pinning of dislocations at 390K, and the overall variation indicated a true stacking-fault energy increase with temperature (figure 5). This conclusion was supported by calculations of the temperature derivative of the stacking-fault energy from thermodynamic data.

Temperature Variation of the Intrinsic Stacking Fault Energy of a High Manganese Austenitic Steel. L.Remy: Acta Metallurgica, 1977, 25[2], 173-9

Figure 5

Stacking-Fault Energy of Fe-20Mn-4Cr-0.5%C

           as a Function of Temperature