Influence of the Strengthening Curve on the Axial Stress in Round Rod on Drawing

Abstract

For the drawing of round rod in conical drawplates, the boundary problem is solved on the basis of the Amontons–Coulomb frictional law for materials in which strengthening corresponds to the equation σ_s/σ_s0 = 1 + m(ln λ)ⁿ. The influence of the parameters m and n of the strengthening curve on the axial stress σ_x in the reducing section of the drawplate is established. The new result is compared with existing solutions. It is found that, if the strengthening law is replaced by approximate functions without taking account of the shape of the strengthening curve at small n, the calculated values of σ_x are too low, by 15–25%.