| 摘要 |
The invention relates to metal forming, in particular, to the shaping of sheets by bending in cold condition and it is intended for use at production of two-seam welded pipes. In the method, which includes the bending of sheet by several sequential deformations of one sign, straightening billet by fulfilling the deformation of opposite sign and final bending of billet due to its springing after preliminary straightening, the process of straightening is performed not less than in two stages, between which deformation of opposite sign is carried out. The method provides for compensation for strengthening the metal of bendable sheet by its weakening. This will allow excluding crack formation in semi-cylindrical tube billets, and accordingly to reduce the amount of pipes, which are subject to rejection. |
