Electropulsing Treatment Overcomes the Strength–Ductility Trade‐Off of Cold‐Drawn Pearlitic Steel Wire

This work systematically studies the evolution mechanism of the steel wire's mechanical properties and microstructure during electropulsing treatment (EPT) using X‐ray diffraction, transmission electron microscopy, and atomic probe tomography, combined with molecular dynamics simulations. The results reveal that, under EPT treatment parameters of 15.8 A mm −2 , 300 Hz, and 120 s, the tensile strength of the steel wires increases from 2172 to 2332 MPa (a 7.4% increase), while the elongation to failure improves from 5.5% to 6.0% (a 9.1% increase), achieving a simultaneous improvement in both strength and ductility. Microstructure analysis indicates that the increase in steel wire strength is attributed to the following two reasons: EPT treatment promotes the transformation of amorphous cementite into a nanocrystalline structure, enhancing the dislocation pinning effect. Concurrently, C atoms migrate into the ferrite matrix, resulting in a solid solution strengthening effect. The improvement in plasticity is mainly because EPT disrupts the continuity of the cementite lamellae, thereby weakening its constraint on dislocation slip.