全浮动芯棒连轧管机组孔型修改效果初探

 针对全浮动芯棒连轧管机组孔型系统的修改过程，通过生产实验实时记录力能参数，并离线抽取荒管获得钢管壁厚分布曲线，随后进行对比，得到如下结论：连轧钢管壁厚分布具有螺旋形特征，纵向上最大和最小壁厚以波峰与波谷形式交替出现；孔型修改后，钢管壁厚精度降低，力能参数有所升高。分析其原因，孔型修改后，第3、5机架孔型椭圆度增大，加大了钢管压扁变形与金属横向壁厚增厚，并且机组的张力状态未能有效减弱金属横向流动趋势，最终导致壁厚不均率及力能参数升高。

Preliminary Study on Influences of Groove Change of Full Floating Mandrel Mill

The groove change process of full floating mandrel mill is investigated, through recording rolling parameters during producing experiments and attaining wall thickness uniformity figure in off line measurement, and the conclusion drawn from the experiments is that the wall thickness distribution has spirality characteristic, and the maximal and minimal wall thickness appears alternately corresponding to wave crest and wave trough. After rolled in changed groove, wall thickness uniformity decreases, and rolling pressure and electric current increase. It has been found that for rolling in changed groove, the pitch of oval increases that deepens the flattening process and the transverse increase of wall thickness, at the same time, the enactment of tension in the whole mill can not weaken the trend of transverse metal flow, so that the wall thickness nonuniformity and rolling parameters in each mill will increase obviously.