| 摘要 |
PURPOSE:To eliminate a rolling flaw and dirt by specifying the ratio of the diameter of lower work roll and diameter of upper work roll with a three step roll arrangement. CONSTITUTION:In case of performing a skin-pass rolling of <=5% rolling reduction rate a three step roll arrangement is made with a pair of upper and lower work rolls and a lower stay roll 2'. In case of the diameter of the lower work roll 1, 1' being D and the diameter of the upper work roll 1 being D', D'/D is regulated to >=1.4. The rolling flaw and dirt easily caused by a wet type skin- pass rolling in a four step rolling mill are thus eliminated. The slipping between the upper work roll and upper stay roll is avoided as well. |
