Pass-Schedule Design for Non-circular Wire Drawing

To establish a designing method of drawing schedule of the wire with an elliptic cross-section, the influence of the cross-sectional shape and the reduction in cross-sectional area on underfilling and drawing limit has been investigated by experiments and numerical analyses. It is found that under the conditions where the axis ratio (major length / minor length) is less than 1.3, the underfilling is suppressed when the reduction is greater than 20%. However, the wire fractures if the reduction is higher than 50%. It is confirmed that the lateral spread by the drawing is very small, about 2 to 3%, and not sensitive to the reduction. Based on the above results, it is concluded that the wire diameter before the drawing should be designed larger than the major length of the die. Furthermore, by considering underfilling, drawing limit and die seizure, a method to find the designable window of the reduction in cross-sectional area and the axis ratio of the cross section for single-pass wire drawing will be presented.