摘要:
A wire rod according to the present invention includes a predetermined chemical composition and the remainder thereof includes Fe and impurity, wherein the average value of a grain size of a pearlite block in a cross section perpendicular to a wire rod axial direction is 23µm or less, and wherein a number density of the pearlite blocks having a grain size of 40µm or more in the cross section perpendicular to the wire rod axial direction is 0 to 20 pieces/mm 2 .
摘要:
The present invention provides a wire rod having good wire drawing characteristics stably in actual production and a method for production of such wire rod. The wire rod has a chemical composition including, by mass%, C: 0.7 to 1.2%, Si: 0.1 to 1.5%, Mn: 1.0% or less, N: 0.005ppm or less, and a balance of Fe and unavoidable impurities, wherein 80% or more of a microstructure is a bainite structure and a remaining microstructure is a nonbainite structure in a cross-section of the wire rod, wherein a full width at half maximum of a (211) crystal face of a ferrite phase in the structure of the wire rod cross-section is 0.6° or less, wherein a tensile strength TS (MPa) and reduction of area RA (%) respectively satisfy the following formula (1) and the following formula (2), and wherein a standard deviation of hardness distribution of Vickers hardness (Hv) in the cross-section is less than 6. TS ‰¤ 580 + 700 × C RA ‰¥ 100 ˆ’ 46 × C ˆ’ 18 × Mn ˆ’ 10 × Cr