Influence of Strain Hardening Rate of Material on Temperature and Strain Distributions during Wire Drawing

Abstract

Temperature rise of a specimen is a significant issue in drawing industries for wire, rod, and bar products, because an excessive increase in temperature during the drawing process can deteriorate the product quality and die life. The influence of the strain hardening exponent (n) of a wire on the temperature and strain distributions during wire drawing is investigated to understand its effect and to improve the quality of drawn wire. Finite element analysis and experiments are conducted to analyze the temperature and strain distributions of wires with n values of 0.0, 0.1, 0.5, and 1.0. The temperature increase of the wire augments as the n of the wire increases, despite the same amount of ideal plastic deformation, which is associated closely with the redundant work. The shear strain increases with the n of the specimen, which generates redundant work, leading to a high temperature rise. Similarly, drawing force increases with the n of the specimen, owing to the increase in redundant work with the n of the wire. In addition, the drawing force presents a linear relationship with the temperature rise of the wire. The drawing speed should be reduced and/or the cooling of wire and die should be strengthened during wire drawing, with increasing n value of the wire, because product quality and die wear are highly associated with the temperature rise of the wire in the deformation zone.