| 摘要 |
PURPOSE:To provide superior workability by coiling a hot rolled steel sheet at a high temp. and holding the resulting coil hot at once. CONSTITUTION:A low-C Al killed steel slab is heated to 1,000-1,280 deg.C and hot rolled. The hot rolled steel sheet is coiled so as to keep the central part of the resulting coil at >=600 deg.C and the internal part at 750-850 deg.C. A cover with high heat resistance is put on the coil within 10min after finishing the coiling, and the coil is slowly cooled at 1.3-5 deg.C/min average cooling rate while the temp. of the external part of the coil falls from 650 deg.C to 550 deg.C. The cooled coil is cold rolled and annealed continuously. |
