HOT-ROLLED WIRE ROD, EXCELLENT IN WIRE DRAWABILITY, ALLOWING HEAT TREATMENT PRIOR TO WIRE DRAWING TO BE OMITTED

摘要

A hot-rolled wire rod:the wire rod being a hot-rolled wire rod 5.0 mm or more indiameter, containing in massC: 0.6 to 1.0%,Si: 0.1 to 1.5%,Mn: 0.3 to 1.0%,P: 0.02% or less, andS: 0.02% or less;not less than 90% of the wire rod in area percentage beingcomposed of a pearlite structure; andthe mechanical properties of the wire rod 4 m in lengthsatisfying the following expressions (1) to (4),(1) TS*-30 = Average value of tensile strength (TS AVin MPa) = TS*+30,where, TS* = 400 × {[C]+([Mn]+[Si])/5}+670 and theelements in square brackets [ ] in the equality mean thecontents of relevant elements in percentage,(2) Standard deviation of tensile strength (TS.sigma.) = 30MPa,(3) Average value of reduction of area (RA AV) 35%,(4) Standard deviation of reduction of area (RA.sigma.)= 4%.A hot-rolled wire rod according to the presentinvention is incomparably excellent in wire drawability andbrakes less frequently than a conventional wire rod evenwhen it is processed as hot-rolled with heat treatment suchas patenting treatment omitted.