POSCO Holdings Inc.
Non-heat treated wire rod having excellent cold workability and manufactured method therefor

Abstract:

Disclosed are a non-quenched and tempered wire rod and a manufacturing method therefor, the non-quenched and tempered wire rod comprising in percentage by weight: 0.15 to 0.30% of C; 0.05 to 0.3% of Si; 1.0 to 2.0% of Mn; 0.5% of less of Cr (except for 0%); 0.02% or less of P; 0.02% or less of S; 0.01 to 0.05% of sol. Al; 0.005 to 0.02% of Nb; 0.05 to 0.2% of V; 0.01% or less of N; Fe as the remainder; and unavoidable impurities, wherein the non-quenched and tempered wire rod satisfies the following formulas 1 and 2, wherein, when the hardness of the wire rod measured in 1/2d position and in 1/4d position in the diameter direction of the wire rod is Hv,.sub.1/2d(Hv) and Hv,.sub.1/4d(Hv), respectively (here, d is the diameter of the wire). (Hv,.sub.1/2d+Hv,.sub.1/4d)/2.ltoreq.240 [Formula 1] Hv,.sub.1/2d/Hv,.sub.1/4d.ltoreq.1.2 [Formula 2]