HIGH-CARBON STEEL ROD WIRE OR STEEL WIRE EXCELLENT IN WORKABILITY IN WIRE DRAWING AND PROCESS FOR PRODUCING THE SAME

摘要

A high-carbon steel rod wire or steel wire excellent in workability in wire drawing and a process for producing the same. The wire contains on the weight basis 0.70-1.20 % of carbon, 0.15-1.00 % of silicon and 0.30-0.90 % of manganese; at least either 0.006-0.100 % of aluminum or 0.01-0.35 % of titanium; not more than 0.02 % of phosphorus and not more than 0.01 % of sulfur; and the balance consisting of iron and inevitable impurities. Further it has a microstructure wherein the area rate of the upper bainite structure formed by two-stage transformation is 80 % or above and the Hv value is 450 or less. It may further contain 0.10-0.50 % of chromium as the alloying component. The invention process enables producing a high-carbon steel rod wire or steel wire excellent in workability in wire drawing and can dispense with an intermediate heat treatment in the secondary working steps, thus remarkably lowering the production cost, shortening the working period, and reducing the equipment cost.