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 0.80-0.90 % of carbon, 0.10-1.50 % of silicon and 0.10-1.00 % of manganese; not more than 0.02 % of phosphorus, not more than 0.01 % of sulfur and not more than 0.003 % of aluminum; and the balance consisting of iron and inevitable impurities. Further is 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 0.10-1.00 % of chromium as the alloying component. The invention wire can be drawn at a high reduction of area as compared with the conventional wire and is improved in delamination resistance. 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.