Hot milled wire rod excelling in wire drawability and enabling avoiding heat treatment before wire drawing

Abstract

A hot-rolled wire rod: the wire rod being a hot-rolled wire rod 5.0 mm or more in diameter, containing in mass C: 0.6 to 1.0%, Si: 0.1 to 1.5%, Mn: 0.3 to 1.0%, P: 0.02% or less, and S: 0.02% or less; not less than 90% of the wire rod in area percentage being composed of a pearlite structure; and the mechanical properties of the wire rod 4 m in length satisfying the following expressions (1) to (4), (1) TS*−30≦Average value of tensile strength (TSAV in MPa)≦TS*+30, where, TS*=400×{[C]+([Mn]+[Si])/5}+670 and the elements in square brackets [ ] in the equality mean the contents of relevant elements in percentage, (2) Standard deviation of tensile strength (TSσ)≦30 MPa, (3) Average value of reduction of area (RAAV)>35%, (4) Standard deviation of reduction of area (RAσ) ≦4%. A hot-rolled wire rod according to the present invention is incomparably excellent in wire drawability and brakes less frequently than a conventional wire rod even when it is processed as hot-rolled with heat treatment such as patenting treatment omitted.

Dependencies are inferred from the claim text.