Abstract: The effect of C content (0.014 similar to 0.39 wt pet) on the paramagnetic-antiferromagnetic transition and gamma --> epsilon martensitic transformation of Fe-24Mn alloys has been investigated by the resistivity, dilation, tensile properties measurement and microstructure examination. The results have shown that C decreases T-N, increases the thermal expansion coefficients both above and below the Tu, increases the resistivity above the TN and antiferromagnetic scattering resistivity below TN. It strongly depresses the gamma --> epsilon martensitic transformation and reduces the Ms of Fe-24Mn alloys. Moreover, it increases the lattice parameter of austenite, enhances the tensile ductility, but almost does not affect the tensile strength. With increasing C content from 0.014 to 0.19 wt pet, the yield strength of Fe-24Mn alloy decreases obviously arising from the decreasing of preexisting epsilon martensite, but it increases from 0.19 to 0.39 wt pet C due to the solution hardening of C.

Key words: