| 摘要 |
A method of forging pipes includes drawing a hollow preform by contoured dies on a mandrel. First, drawing the perform is performed on a conical mandrel, then - on a mandrel, consisting of a cylindrical core and a sleeve placed over the core, by the contoured dies with reduction no more than 0.1 of the perform outer diameter with constant tilting at an angle of 15-30 degrees. The sleeve length is 1 ... 2 of the die width, it has the outer conical surface with a taper angle more than the friction angle, and it is set so that at the metal deformation a deformation zone in the preform is always in contact with its outer surface. |
