Strain Hardening in Multipass Drawing of a Round Nonhollow Profile

Resumo

The boundary problem for the drawing of a round nonhollow profile in conical die is solved on the basis of the Amontons–Coulomb friction law for preliminarily strengthened metals, whose strengthening is described by the formula σ_s/σ_s0 = 1 + mεⁿ. Taking account of the initial strain, the influence of the parameters m and n of the strengthening curve on the axial stress σ_x in the narrow section of the drawplate and the distribution of the normal stress over the contact surface may be established. On the basis of the solutions obtained, the form of the strengthening curve may be taken into account in calculating the reduction conditions for the multipass drawing of wire and rod. The proposed solutions are compared with existing solutions.