| 摘要 |
PURPOSE:To transform uniformly austenite to pearlite by cooling the closed ring pitch under the specified condition after a heat rolled wire rod of middle and high carbon is coiled like a non-concentric ring and induced in a heat treating tank for controlled cooling. CONSTITUTION:A wire rod immediately after heat rolling is made into a non- concentric ring wire rod 4 in a loop player 3 and is loaded in a cooling medium 8 of a heat treating tank 7 through conveyers 5, 6. The cooling medium 8 uses about 60-100 deg.C hot water which is produced by mixing cooled water and hot water of a cooling water tank 32 and a hot water storage tank 33, and most of austenite are transformed almost uniformly into a fine pearlite structure by controlled cooling throughout the full length of a wire rod 4. Thereafter, a ring pitch of the non-concentric ring wire rod 4 is reduced to about 1/10 by the fall difference and speed difference between an upper oblique conveyer 11 and transferring out conveyer 12, held in a heat holding tank 13 while 60-300sec and the residual austenite is transformed to pearlite to send a collector 18. |
