| 摘要 |
PURPOSE:To increase the tensile strength of a wire rod to >=120kgf/mm.<2> by contg. specific carbonitride forming elements and subjecting the wire rod to finish rolling followed by direct patenting in producing a high carbon high tensile wire rod. CONSTITUTION:A steel ingot contains 0.5-1.5% C, <1.5% Si, <0.4% Mn, and 0.2-2.0% Cr, and further <=0.3% one or more kinds of Al, Ti, Nb, V, Zr are contained as carbonitride forming elements. Such steel ingot is heated to above 1,050 deg.C, after which it is bloomed, and is then cooled at >=50 deg.C/hr cooling rates, whereby it is made into a billet. This billet is heated to temps. above the AC3 point and is finish rolled at 500-1,000 deg.C to a wire rod, after which it is directly patented by utilzing said temps. The sorbite structure of good tenacity and elongation is formed, and its tensile strength is >=120kgf/mm.<2>, thus the steel wire rod suited for piano wires, PC steel wires is obtained. |
