| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for producing a low yield ratio, high toughness, fire resistant wide flange shape which has uniform mechanical properties in each part. SOLUTION: A slab to which Ti is further added after the control of the concentration of dissolved oxygen by preliminary deoxidation treatment for making rolling temperature histeresis in an unrecrystallized region close among the three points of a flange, fillet and a web is used as the stock. For example, the total draft, the difference in finishing temperature among the part and the finishing temperature in each part in an unrecrystallized region are controlled, so that the low yield point, high toughness, fire resistant wide flange shape having uniform mechanical properties is produced.</p> |
