| 摘要 |
PURPOSE:To obtain a rolling material of high dimensional accuracy without the formation of coarse crystal particles of the product after rolling by specifying the respective rolling reductions of the 1st-3rd stands of alternately vertical and horizontal types which roll a blank material of an oval sectional shape introduced into a finishing mill train. CONSTITUTION:For example, a blank material 1 of an oval sectional shape is introduced in the rolling mill 6 configuration consisting of, for example, 1st-3rd stands 10-12 of vertical-horizontal-vertical types, and is rolled in order of the stands 10, 11. At this time, the material is rolled under light screw down of 3- 8% and 0.5-5% rolling reductions respectively in reduction of area. Then, in the stand 12, it is rolled under ordinary screw down of about 12-20% rolling reductions, whereby it is finally rolled to a circular section, and a product 5 is obtd. The calibers of the stands 10, 11 are formed by locating the short diameter sides of an oval sectional shape parallel and perpendicularly respectively to the axis of rolls 2 as shown by 3 and the caliber of the stand 12 is formed to a circular sectional shape as shown by 4. |
