| 摘要 |
A slab 60 of rectangular section is formed into a pre-blank by rolling it in a passage 61 whose base width is less than or equal to the thickness of the slab used and whose lateral faces are inclined by an angle alpha 1 which is a function of the dimensions of the blank. The rolling upsets the slab ends into mushroom shapes having a thickness of roughly 12% of the slab thickness. The rolling may be carried out using vertical or horizontal rolls. Rolling is completed by carrying out conventional profiling passage rolling to produce the pre-blank 63 and blank 64. <IMAGE> |
