Impact of Die Radius in a Streamlined Die during Wire Drawing

Abstract

The effects of die radius in a streamlined die on design factors, such as the distribution of strain, stress, temperature, damage, and drawing force of a wire, were investigated during wire drawing for a better understanding of streamlined die and improvement in drawing quality of the wire. A numerical simulation was performed with the die radius of the streamlined die. The behavior of the design factors of the drawn wire fabricated by the streamlined die was different from that of the conventional die and was highly dependent on the die radius. The different behaviors of the design factors with the die radius can be explained by the frictional work and redundant work of the wire with die angle. The temperature rise and drawing force were high at a greater die radius because of the great frictional stress and heating effect stemming from the high contact length of the wire and die. Meanwhile, the higher redundant work at the surface area with decreasing die radius led to higher strain inhomogeneity, effective stress, damage value, temperature rise, and drawing force due to the abrupt change in the metal flow of the wire stemming from the high die angle. After the optimization of several design factors with die radius, it was concluded that the optimum IDR values ranged from 0.14 to 0.18, indicating that a streamlined die with a radius of 70 to 90 mm was the most suitable in the present process condition. In particular, the damage value of the wire was reduced in this range of die radii compared to the conventional die.