Damage Analyses and Crack Propagation of Wire Drawing With Central Inclusion Under Different Compression Ratios

The problem of wire breaking in the production of steel cord has always attracted much attention. The research on the mechanism of crack propagation caused by drawing damage is still to be urgently solved in engineering. Therefore, the fracture morphology of cord steel during drawing and the internal micro-defects of steel wire are analyzed by SEM. On this basis, a continuous multi-pass drawing model of steel wire with central inclusions under different compression ratios is established by FEM. The process of crack propagation caused by damage is realized in the simulation. The results show that the larger the size of the inclusion is, the easier it is to form a V-shaped crack propagation path at the front of the inclusion. With the decrease of the compression ratio under the total drawing strain, the internal damage increment of the steel wire increases gradually after multi-pass drawing, which will increase the failure probability of the steel wire as a whole. In particular, the damage of the intact steel wire increases linearly when the compression ratio R = 12%. After seven-pass drawing, the maximum damage value reaches 0.117, which increases by 0.049 and 0.032 compared with the compression ratio R = 20% and R = 16%, respectively.