| 摘要 |
PROBLEM TO BE SOLVED: To prevent the development of longitudinal crack and breakout of the restrictive solidified shell caused by uneven cooling and also, to profitably improve the condition of surface characteristic of a cast slab by restraining the surface flaw. SOLUTION: On at least upper half part of the inner wall of a mold contacting with molten steel, the ruggedness satisfying (1) >3mm, 80mm >=in width or diameter of the recessed part in the horizontal direction, (2) 100-1000μm in depth of the recessed part and (3) 50-95% in area ratio of the recessed part, are given.
|
