Wire rod for concrete reinforcing steel fiber, steel fiber, and manufacturing method therefor

A method of manufacturing a wire rod for concrete reinforcing steel fiber, the method comprising:

• heating a billet comprising, in percent by weight (wt %), 0.01 to 0.04% of C, 0.07 to 0.3% of Si, 1.0 to 2.0% of Mn, 0.1 to 0.3% of P, the remainder of Fe and other unavoidable impurities;
• and
• preparing a wire rod by hot rolling the billet at 1000 to 1150° C. or finishing rolling the billet at A3-70° C. to A3° C.;
• winding the prepared wire rod;
• and
• cooling the wound wire rod to A1° C. at 1 to 5° C./s and then cooling at 15 to 20° C./s from A1° C. to 200° C.

A concrete reinforcing steel fiber comprising:

• in percent by weight (wt %), 0.01 to 0.04% of C, 0.07 to 0.3% of Si, 1.0 to 2.0% of Mn, 0.1 to 0.3% of P, the remainder of Fe and other unavoidable impurities,
• wherein the concrete reinforcing steel fiber satisfies the following Formula (3):
• TSF−TSWR−[15/(1.5*FGS0.1)]*e4.61≥0 (3)
• (in Formula (3), TSF refers to tensile strength of steel fiber, TSWR refers to tensile strength of the wire rod, and FGS refers to an average ferrite crystal grain size).