Pipe production by cold Pilger process

摘要

Production of pipes by the cold Pilger step process by means of two roll stands (1, 2) driven by a crank mechanism at least for some of the time back and forth in opposition to one another is claimed. Most of the forming takes place in the first roll stand (1), while a smaller proportion of forming and additionally smoothing takes place in the second roll stand. Reduction rolling takes place in both roll stands over a mandrel which is adapted to the roll grooves of these stands. While the stand (1) performs the forming forward motion, the stand (2) performs a largely reduction-free return motion. Also claimed is the apparatus which includes a roll stand (1) as a breakdown stand which has rolls (7) provided exclusively with forming grooves, while the roll stand (2) has rolls (8) provided with forming and smoothing grooves.