Process for producing patented steel wire

Abstract

This invention discloses a process for producing a high strength filament, said process comprising the steps of: (1) heating a steel wire to a temperature which is within the range of about 850.degree. C. to about 1100.degree. C. for a period of at least about 2 seconds; wherein said steel wire consists essentially of about 96.61 to about 98.905 weight percent iron, from about 0.72 to about 1.04 weight percent carbon, from about 0.3 to about 0.8 weight percent manganese, from about 0.05 to about 0.4 weight percent silicon, from about 0.02 to about 0.3 weight percent copper, and from about 0.005 to about 0.85 weight percent of at least one member selected from the group consisting of chromium, vanadium, nickel and boron, with the proviso that the total amount of silicon, manganese, chromium, vanadium, nickel and boron in the microalloyed high carbon steel is within the range of about 0.7 to 0.9 weight percent to produce a heated steel wire; (2) continuously cooling the heated steel wire at a cooling rate of less than about 60.degree. C. per second until a transformation from austenite to pearlite begins; (3) allowing the transformation from austenite to pearlite to proceed with an increase in the wire temperature resulting from recalescence to produce a patented steel wire; (4) cooling the patented steel wire to ambient temperature; (5) brass-plating the patented steel wire to produce a brass-plated wire; and (6) cold-drawing the brass-plated steel wire to a diameter which is within the range of about 0.10 mm to about 0.45 mm to produce a high strength filament.