HIGH-STRENGTH WIRE ROD EXCELLING IN WIRE DRAWABILITY AND PROCESS FOR PRODUCING THE SAME

摘要

The invention provides wire rod excellent in drawability and steel wire made from the wire rod as starting material with high productivity at good yield and low cost. A hard steel wire rod of a specified composition is hot rolled, the hot-rolled steel is coiled in a specified temperature range, and the coiled steel is subjected to patenting at a predetermined cooling rate, thereby affording a high-carbon steel wire excellent in workability. It is high-strength steel wire excellent in drawability comprising a pearlite structure of an area ratio of 97% or greater and the balance of non-pearlite structures including bainite, degenerate-pearlite and pro-eutectoid ferrite and having a pearlite block size of not less than 20 µm and not greater than 45 µm. The invention also provides a high-carbon steel wire excellent in ductility, which is manufactured by subjecting the wire rod to intermediate patenting and cold drawing and has a tensile strength of 2800 MPa or greater.