Influence of die-wire contact length ratio on chevron crack and optimum drawing condition in wire drawing

摘要

The internal stress during wire drawing and the residual stress after wire drawing have been analyzed by the elastoplastic finite-element method (FEM). The die-wire contact length ratio l/d{sub}0 (the contact length/the diameter before drawing)affects the stress, temperature and residual stress distributions during wire drawing. The mean stress, which influences chevron cracks due to internal stress of the central part, was found to be maximum at the contact length ratio of 0.1, andsimultaneously, the surface residual stress was also maximum. In addition, the mean stress which influenced the optimum drawing condition, due to internal stress of the central part, was found to be at a minimum value of 0 at the contact length ratio of0.55, and at the same time, the surface residual stress was less than one-half its value at the contact length ratio of 0.1.