Electrical resistivity of steels and face-centered-cubic iron

• Literature data for the electrical resistivity of austenitic and ferritic steels are analyzed in a model that takes into account their composition and microstructure. The resistivity in these systems is so high that one must allow for its saturation. That effect is described with the shunt-resistor model, and saturation at 1.68 muOmegam. Our analysis yields the contributions to the resistivity of austenite per weight percent from the solute elements N, C, Nb, Si, Ti, Cu, Ni, Cr, and Mo, with the contribution decreasing in this order. For ferrite, the contribution of the solute elements Si, Mn, Cu, Ni, Mo, and Cr was determined, with the contribution decreasing in this order. The data allow us to obtain the previously unknown resistivity of metastable pure gamma-iron (fcc Fe) near room temperature, and find an interpolation formula for the resistivity up to 1183 K where the gamma phase becomes stable. The resistivity in metastable gamma-iron is significantly larger than the resistivity in stable alpha-Fe (bcc Fe) below 1000 K. This difference is attributed to a strong electron scattering due to spin disorder in gamma-iron at intermediate temperatures.

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