The Combined Effect of Ti, Nb, and V Microalloying on Microstructure and Mechanical Properties of High‐Carbon Steel Wire Rod

This study investigates the effects of Ti, Nb, and V additions, both individually and in combination, on the microstructure and mechanical properties of high‐carbon pearlitic steel wire rods for bridge cables. Through comparative analysis of single element (Ti, Nb, and V) and composite microalloyed steels, it is demonstrated that Ti–Nb–V coaddition significantly refines pearlite lamellar spacing (127.7 nm) and nodule size (3.4 μm), attributed to the precipitation of (Ti, Nb, V)C particles. Thermodynamic and kinetic models predict an average precipitate size of 17.2 nm at 600 °C, closely matching experimental results (19.4 nm, 11.34% deviation). Mechanical testing reveals that Ti–Nb–V steel achieves superior yield strength (1297 MPa), with interface strengthening contributing 78.9% of the total strength, followed by precipitation strengthening. The balanced strength–ductility combination (13.2% elongation) highlights the efficacy of composite microalloying in optimizing high‐performance bridge cable steel.