| 摘要 |
PURPOSE:To produce a cold rolled steel plate of stable quality at a low cost by taking up an ordinary low carbon steel to a coil at hgih temps. after hot rolling and forcibly cooling the same with water under specific conditions within the prescribed time after the coiling. CONSTITUTION:The ordinary low carbon steel consisting of<=0.10%C, <=0.1%Si, <=0.50%Mn, <=0.05%P, <=0.05%S, and the balance consisting of Fe and unavoidable impurities is hot-rolled. This hot-rolled steel plate is wound to a coil at below 800 deg.C, and after the coiling, it is colled with water down to below 650 deg.C at >=2 deg.C/min cooling rate within 30sec-40min after the coiling. Then, the pickling efficiency equivalent to that for ordinary low temp. coiled materials can be assured. After the water cooled steel plate is pickled, it is cold-rolled at ordianry drafts, and is subjected to annealing treatment in an ordinary continuous annealing furnace, whereby the cold rolled steel plate of stable quality for general pressing is produced. |
