HOT MILLED WIRE ROD EXCELLING IN WIRE DRAWABILITY AND ENABLING AVOIDING HEAT TREATMENT BEFORE WIRE DRAWING

摘要

A hot milled wire rod of 5.0 mm or greater diameter comprising: C: 0.6 - 1.0% (in terms of mass%, hereinafter applicable), Si: 0.1 - 1.5%, and Mn: 0.3 - 1.0%, wherein P: is limited to 0.02% or less, and S: is limited to 0.02% or less, and whose 90 area% or more is constituted of pearlite structure. This hot milled wire rod exhibits, at a length of 4 m, mechanical properties satisfying: (1) TS*-30 <= average of tensile strength (TSAV:MPa) <= TS*+30, wherein TS* = 400x{[C]+([Mn]+[Si])/5}+670 in which [ ] means the content (%) of each element; (2) standard deviation of tensile strength (TSsigma) <= 30MPa; (3) average of rupture area reduction (RAAV) > 35%; and (4) standard deviation of rupture area reduction (RAsigma) <= 4%. This hot milled wire rod highly excels in wire drawability only through hot milling even when heat treatment such as patenting is avoided and enables striking reduction of wire breakage frequency as compared with that of conventional rods.