| 摘要 |
PURPOSE:To make a descaling stage and a hardening stage unnecessary by hot rolling a steel contg. specified amounts of C, Si, Mn, Cr, B and Ti and/or Al to form a wire rod, converting the structure of the rod into martensite, and drawing the rod through roller dies without carrying out descaling. CONSTITUTION:A steel consisting of, by weight, 0.1-0.4% C, 0.05-1.5% Si, 0.7-2.5% Mn, 0.1-1.5% Cr, 0.0002-0.005% B, 0.005-0.05% Ti and/or 0.007- 0.05% Al and the balance Fe with inevitable impurities is hot rolled to form a wire rod. The structure of the rod is converted into martensite by controlled cooling from <=700 deg.C after the hot rolling, and the rod is drawn through roller dies without carrying out descaling. The drawn rod may be deformed or further tempered and subjected to temp. adjustment. |
