Computer Simulation of Micro-Mechanic in Pearlitic Steel Wire Drawing

Cold-drawn high-carbon steel wire with pearlite microstructure is one of the most popular raw materials for modern reinforcing ropes. Lamellae thinning, changes in interlamellar interface and metallographic texture, strain localization is the main property-forming phenomena in the wire drawing process. However, the experimental study of these phenomena dynamics is difficult and time-consuming. Drawing process of pearlitic steel wire was investigated. Behavior of pearlite colonies on the surface and the central layer of the wire were researched, based on the multiscale computer simulation. Cementite lamellae orientation in relation to the drawing axis, interlamellar spacing and shape of cementite inclusions were key factors. Regularities of the pearlite colonies reorientation, changing the shape and size of cementite lamellae and strain localization in the ferrite were established on the basis of FEM. It was established that the cementite lamellae, that are parallel to the drawing axis, had the maximum thinning. Interlamellar distance in pearlite colonies with such lamellae changed most intensively. Cementite lamellae, that are perpendicular to the drawing axis, are the most susceptible to fracture. It was found out that for certain values interlamellar distance this effect can be reduced. Intensive reorientation of pearlite colonies in relation to the drawing axis was observed in the case of their location at an angle to the drawing direction. At the same time, there was a significant bending of cementite lamellae and their susceptibility to fragmentation. Estimated values of the wire mechanical properties were compared with a real experiment. The simulation results were verified by metallographic analysis.