The causes producing wall thickness difference in a same pierced shell are expounded and the influences of piercing, rolling and mandrel drawing on the difference are studied.
阐述了穿孔毛管产生同管壁厚差的原因，研究了穿孔和轧管工艺对钢管同管壁厚差的影响。
2
And also a rolling optimum controller, which keeps the mandrel feed in rate as requirement, is designed and relative formulas are given.
介绍了一种环轧过程最优控制器的设计方法，该控制器可以使压力辊按要求的进给速率运动。
3
Working principles: Tool using a self-centering theory, generated through the mandrel roller adjustment hitting, rolling motion.