Electrical resistivity of steels and face-centered-cubic iron

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Abstract
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 μΩm. 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 γ-iron (fcc Fe) near room temperature, and find an interpolation formula for the resistivity up to 1183 K where the γ phase becomes stable. The resistivity in metastable γ-iron is significantly larger than the resistivity in stable α-Fe (bcc Fe) below 1000 K. This difference is attributed to a strong electron scattering due to spin disorder in γ-iron at intermediate temperatures.