The invention discloses a low-cost, high-strength and low-yield-ratio
wire rod for a
rivet nut and a preparation method of the
wire rod, and belongs to the field of metallurgical production of wire rods. The
wire rod comprises the following chemical components in percentage by weight: 0.19 to 0.23 percent of C, 0.35 to 0.55 percent of Si, 1.30 to 1.60 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.005 percent of S, 0.25 to 0.35 percent of Cr, 0.002 to 0.020 percent of Al and the balance of Fe and inevitable impurities. The preparation method comprises the steps of
smelting and
casting, cogging, wire rod controlled rolling, cooling and the like, and the grain size of a wire rod is controlled to be 5-6 levels by optimizing component design (solution strengthening is mainly conducted on low-cost Si and Mn elements) and technological parameters (high-temperature heating, precise controlled rolling and controlled cooling, low-Al design and the like); the tensile strength of the
rivet nut manufactured through follow-up modification, cold heading and annealing treatment reaches 530-610 MPa, the yield strength ranges from 320 MPa to 360 MPa, the
yield ratio is smaller than or equal to 0.6, the 10.9-level requirement is met after riveting hardening, the production cost is remarkably reduced, and the problems that an existing high-level
rivet nut depends on
precious metal, the
yield ratio is high, and
cracking is likely to happen are solved.