Hwang Joong-Ki
School of Mechatronics Engineering, Korea University of Technology & Education, Cheonan 31253, Korea.
Materials (Basel). 2022 Apr 18;15(8):2939. doi: 10.3390/ma15082939.
The different behaviors of the mechanical properties of drawn and caliber-rolled wires with applied strain were investigated to determine the appropriate process between wire drawing and caliber rolling with consideration of materials and process conditions. Ferritic, pearlitic, and TWIP steels were drawn and caliber-rolled under the same process conditions. Caliber-rolled wires exhibited a hardening behavior in the early deformation stage and softening behavior in the later deformation stage compared with the drawn wires, regardless of the steel. The hardening behavior of the caliber-rolled wires was explained by the higher strain induced by caliber rolling compared with wire drawing, especially the higher amount of redundant work in caliber-rolled wire. The caliber-rolled wire had approximately 36% higher strain than the drawn wire and approximately 85% higher strain than nominal strain. The softening behavior of the caliber-rolled wire in later deformation stages was related to the Bauschinger effect or low-cycle fatigue effect caused by the roll geometries and loading conditions during caliber rolling. The different intersection points of the tensile strength between drawn and caliber-rolled wires with the steels were attributed to the different strain hardening rates of each steel. Between the options of the caliber rolling and wire drawing processes, the appropriate process should be selected according to the strain hardening rate of the material and the amount of plastic deformation. For instance, when the wires need to deform at high levels, wire drawing is the better process because of the appearance of the Bauschinger effect in caliber-rolled wire.
研究了拉拔丝和定径轧制丝在施加应变时机械性能的不同表现，以便在考虑材料和工艺条件的情况下确定拉拔和定径轧制之间的合适工艺。在相同工艺条件下对铁素体钢、珠光体钢和TWIP钢进行拉拔和定径轧制。与拉拔丝相比，无论何种钢材，定径轧制丝在变形初期表现出硬化行为，在变形后期表现出软化行为。定径轧制丝的硬化行为可解释为与拉拔相比，定径轧制产生的应变更高，特别是定径轧制丝中多余功的量更高。定径轧制丝的应变比拉拔丝高约36%，比名义应变高约85%。定径轧制丝在后期变形阶段的软化行为与定径轧制过程中的轧辊几何形状和加载条件引起的包申格效应或低周疲劳效应有关。拉拔丝和定径轧制丝与钢材之间抗拉强度的不同交点归因于每种钢材不同的应变硬化率。在定径轧制和拉拔工艺这两种选择之间，应根据材料的应变硬化率和塑性变形量选择合适的工艺。例如，当钢丝需要进行大量变形时，拉拔是更好的工艺，因为定径轧制丝中会出现包申格效应。
