The effect of grain refinement by multi-pass continuous hybrid process on mechanical properties of low-carbon steel wires

In this work, a multi-pass continuous hybrid (CH) process simulated by finite element analyses is investigated for producing grain-refined low-carbon steel wires in a continuous manner. The effect of grain-refined microstructure on mechanical properties such as tensile strength, ductility, micro-hardness, and fatigue limit is studied. For this purpose, the multi-pass CH process was experimentally set up and applied up to five passes with route A at room temperature. The experimental findings were compared with those for the multi-pass conventional wire drawing (WD) process. According to the present observation, the five-pass CH process refined the grains in the wires with many well-defined high angle grain boundaries, resulting in enhanced ultimate tensile strength and comparable ductility compared to the WD process. In addition, the fatigue limit of the specimen produced by the CH process was enhanced due to the grain-refined microstructure of the specimen compared to the one of the WD process. Based on the present investigation, it was found that the multi-pass CH process will be more efficient in manufacturing the fine-grained wires with enhanced mechanical properties compared to the WD process.