| 摘要 |
PURPOSE:To enable the working of a sound rolled pipe having a small rate of deviation in diameter without rolling cracks by determining the slide relief rate of roll dies by addition of a difference in diameter basing on the supply rate of a blank pipe material at an optional point, an elastic recovery rate and the rate of deviation in diameter. CONSTITUTION:The side relief rate FX2 of a pair of upper and lower caliber roll dies 4 having caliber grooves 3 on the outside circumference is determined in the following way in pilger rolling for rolling a blank pipe material 2 positioned on a mandrel 1 by means of said dies 4: The relief rate is determined by adding the difference in diameter basing on the supply rate of the material 2 at an optional point in the working region, the elastic recovery rate of the material 2 in the stage of releasing the load therefrom and the rate of deviation in the diameter of the material 2. The relief rate is formed in both shoulder parts of the caliber groove 3, and the caliber groove 3 connecting both shoulder parts and the peak part of the groove respectively with gentle curves is formed over the entire circumference of the roll. |
