A copper-clad steel wire and its preparation method

Abstract

This invention belongs to the field of copper-clad steel wire and discloses a copper-clad steel wire and its preparation process. The wire comprises a steel core, an interface gradient transition layer, and a copper layer. The chemical composition of the steel core, by mass percentage, is: C≤0.010%, Si≤0.010%, Mn≤0.07%, P≤0.010%, S≤0.010%, Al≤0.004%, Ti≤0.003%, B 0.0060~0.0120%, with the balance being Fe, and the total content of other elements ≤0.15%. The steel core has a ferrite structure, with B distributed in a solid solution state, and the average size of inclusions ≤1.0μm. The thickness of the interface gradient transition layer is 0.5~2.0μm, with a continuous gradient change in the content of Fe and Cu elements. The copper layer has a purity ≥99.95% and a thickness of 5~50μm. The wire diameter is 0.05~2.0mm. This invention achieves high strength, high conductivity, and excellent drawing performance in wires through the synergistic effect of high-purity steel core, B microalloying, controlled gradient diffusion, and rapid cooling. The interfacial bonding strength reaches ≥11.5N, and the conductivity is ≥84%IACS.

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