The Deformation and the Redundant Work Factor in the Axisymmetric Drawing of AISI 420 Stainless Steel Bars—Strain Path Effects Analysis

Abstract

In the present work, experimental techniques for evaluating the deformation and the redundant work factor in the axisymmetric drawing of ferritic AISI 420 stainless steel bars were investigated. Six operation conditions, involving two reductions of area and three die semi-angles, were employed in the study. Regarding the redundant deformation analysis, the visioplasticity technique was considered as the most adequate procedure for estimating the average deformation in drawing. In this case, an increasing relationship between the redundant deformation factor and the parameter Δ was obtained. On the other hand, the stress–strain curves superposition technique led to redundant deformation factor values almost insensitive to variations of the parameter Δ and below unity, a phenomenon which was associated with strain path effects. Concerning the redundant work factor study, the experimental results were lower than those obtained through a theoretical approach and, in some conditions, below unity. This was also attributed to strain path effects.