12 mm Thick Circular Blanks of Al-killed AISI 1020 Steel -Applied for Cylindrical Cup Manufacturing by Multistage Deep Drawing with Simultaneous Ironing

Abstract

In this paper a new modified processing route has been proposed for producing long cylindrical cups from 12 mm thick circular blanks of AISI 1020 steel (Aluminium (Al) -killed). In this route, flat blanks were made to preformed shape by stamping operation, followed by multistage deep drawing processes(without blank-holder and with inter-stage stress relief annealing) to increase cup depth. Wall ironing was also purposefully included in each draw step to reduce wall thickness and earing tendency on cup edges. Thus, evolution of wall thickness distribution, Drawability and Ironability, punch force history, and strain distribution profiles on outer cup surfaces were obtained as the effects of interaction between processes, tools and material. The overall draw stages showed: LDR 2.06; overall draw reduction >50% with a drawing efficiency ~72%; LIR 3.55; overall ironing reduction >70% with an ironing efficiency ~68%, which were achieved in the experimental works.

Strain Hardening of Carbon Steel During Wire Drawing

“…To calculate the friction coefficient many method had been proposed: for example, Leu 7 used a model of plastic hemispherical contact against a rigid flat and described the deformed shape as the fractional profile of an ellipsoid, while Ajiboyeet al 8 performed an ANOVA analysis comparing two regression models to predict the shear friction factor at the punch interface. Similar models and experimental analyses are presented by Parida et al 17,18 , Souza et al 13 and Andrade et al 14 . The principal aim of this paper is to compare the hypothesis of strain hardening used by Avitzur in the model proposed in 1 for the calculation of the force in wire drawing with the real behaviour of a carbon steel subjected to an industrial drawing process.…”