Steel wire rod for steel wire rope and preparation method of steel wire rod

The invention relates to a steel wire rod for a steel wire rope, which comprises the following alloy components: 0.49-0.56% of C, 0.15-0.35% of Si, 0.60-0.90% of Mn, less than or equal to 0.020% of P, less than or equal to 0.020% of S, less than or equal to 0.20% of Cr, less than or equal to 0.20% of Ni, less than or equal to 0.20% of Cu and the balance of Fe and inevitable impurities. The tensile strength of the wire rod is 800-920 MPa, the elongation is larger than or equal to 13%, the percentage reduction of area is larger than or equal to 39%, non-metallic inclusions A + C are smaller than or equal to 2.0, B + D is smaller than or equal to 1.5, and the total decarburized layer depth is smaller than or equal to 1.5 Dmm. The preparation technology sequentially comprises the technological steps of 120 t converter, external refining LF, small square billet continuous casting, heating furnace heating, controlled rolling and controlled cooling rolling, channel heat preservation and the like, and the purpose of