Effect of Ring Configuration on the Deviation in Cooling Rate and Mechanical Properties of a Wire Rod during the Stelmor Cooling Process

The temperature of a wire ring with various ring pitch was measured with thermocouples using the experimentally simulated Stelmor cooling process to determine the origin of deviation in cooling rate and mechanical properties of the wire ring. The measured temperature histories of each region within the wire ring were analyzed via a numerical simulation and confirmed based on tensile tests and microstructure evolution. The deviation in cooling rate and mechanical properties of the wire ring mainly occurred due to the upper edge region that cooled very slowly, particularly when the ring pitch was small. The head and tail regions of the wire ring tend to cool fast due to lower packing density, and thus, the strength of the wire rod exceeds that of the middle region. Four conceptual solutions were proposed to decrease the deviation in mechanical properties of the wire ring by reducing the effect of the upper edge region and head/tail regions. These suggestions can aid in designing cooling and working conditions to produce high-quality wire rod steels.