Damage and fracture analyses of wire with V‐shaped microcrack on multi‐pass drawing under back tensions

Abstract

Wire breakage has always attracted much attention in drawing. Mastering the mechanism of drawing fracture can effectively improve the quality of steel wire. In this study, the morphology of the fracture samples is analyzed. There are obvious V-shaped microcracks in the materials by observing the microstructure. Base on the above results, the wire models with V-shaped microcrack of different inclinations are established via the finite element method (FEM). Besides, the multi-pass drawing under different back tension is simulated, and the process from crack propagation caused by damage to fracture is realized. The results show that microcrack has a great influence on the drawing fracture, and inclination is a key factor. With the increase of angle, the propagation rate of crack increases accordingly. Meanwhile, back tension will increase the accumulation of damage. The larger the back tension is, the larger the crack path is, which eventually leads to the formation of pen-tip shaped fracture.