Patent ID: 9267183
Filing Date: 2016-02-23
CPC Classification: B21B,C21D,C22C

Claim Text:
1. A hot-rolled wire rod, comprising Fe; and, based on percent by mass: C: 0.35 to 0.65%; Si: 1.6 to 3.0%; Mn: 0.10 to 1.0%; Cr: 0.1 to 2.0%; P: a positive amount of 0.025% or less; S: a positive amount of 0.025% or less; N: a positive amount of 0.006% or less; Al: a positive amount of 0.1% or less; O: a positive amount of 0.0030% or less; and at least one selected from the group consisting of Mg: 0.1 to 50 ppm; and Ca: 0.1 to 50 ppm; optionally at least one selected from the group consisting of Ni: a positive amount of 1% or less and Cu: a positive amount of 1.0% or less, optionally at least one selected from the group consisting of V: a positive amount of 0.30% or less; Ti: a positive amount of 0.10% or less; Nb: a positive amount of 0.1% or less; and Zr: a positive amount of 0.10% or less, optionally Mo: a positive amount of 1.0% or less, optionally B: a positive amount of 50 ppm or less, and optionally at least one rare earth element: a positive amount of 1.5 ppm or less, wherein the rod has a wire diameter of 9.0 to 25 mm, breakage of the rod does not occur in heavy wire drawing performed under a true strain of 0.42 or more, a content of hydrogen in the rod is 2.50 ppm by mass or less, a hardness HV of the rod is 460×C a maximum value of hardness in the range from 331 HV to 425 HV, and an average grain diameter D