| 摘要 |
PURPOSE:To disappear projection parts generated in preforming stage and to reduce generation of lap flaws during rolling by rolling end parts of a stock by rolling rolls after pressing by pulling back the stock between a pressing and a rolling stages. CONSTITUTION:A top part 2 of a steel stock 1 is inserted between rolling rolls 3 and a thin thick part 4 is formed in the top part 2 by pressing by use of the rolls 3. Then, the stock 1 is slightly pulled back from a position between the rolls 3 after the upper roll 3 is somewhat moved up. Next, a projection end part 5 of the preformed thin part 4 is reversely rolled toward the outside of the stock 1 as shown by a hatched part 7 in the illustration by rolling down use of the upper roll 3. After disappearing the part 5 in the above procedure, the stock 1 is rolled to be subjected to the high quality rolling without lap flaws. |
