Microstructure and Residual Stress of Cold Drawn Pearlitic Wires

Microstructure and residual stress evolution of pearlitic steel during cold drawing was investigated by scanning electron microscope and X-ray diffraction, respectively. With drawing strain increasing, the pearlitic colonies gradually aligned to the drawing direction. It was found that the key factor affecting the flow stress and ultimate tensile strength of drawing rods was the interlamellar spacing of pearlite, in which a Hall-Petch relationship with the parameter k of 567.4 kN.m(-3/2) was established through tensile tests. The XRD results indicated that a work hardening mechanism was contributed to the increasing residual stress in the cold-drawn rods with increasing drawing strain.