Microstructure and Mechanical Properties of Ultra-High Strength Pearlitic Wire in Single-pass Cold Drawing

The effect of compression ratio on the microstructure and mechanical properties of ultra-high strength pearlitic wire in single-pass cold drawing has been studied. The ultra-high tensile strength cord steel with a carbon content of 1.02 wt% were pulled through a single-pass drawing to different compression ratios (0-30%). With the increase of the single-pass compression ratio, the tensile strength, microhardness and torsional properties of the steel wire increased gradually. When the compression rate increased from 0 to 30%, the tensile strength of the steel wire increased from 1263.4 MPa to 1553.7 MPa, the torsional strength of steel wire increased from 1126.83 MPa to 1279.66 MPa. In the single-pass drawing process, the strengthening mechanism of the pearlitic steel wire are mainly the work hardening caused by the dislocation slip in the ferrite, and the fine grain strengthening caused by the decrease of the pearlite sheet spacing.