The relationship between microstructures and ductility parameters, including reduction of area, elongation to failure, occurrence of delamination, and number of turns to failure in torsion, in hypereutectoid pearlitic steel wires was investigated. The transformed steel wires at 620 °C were successively dry-drawn to drawing strains from 0.40 to 2.38. To examine the effects of hot-dip galvanizing conditions, post-deformation annealing was performed on cold drawn steel wires (ε = 0.99, 1.59, and 2.38) with a different heating time of 30–3600 s at 500 °C in a salt bath. In cold drawn wires, elongation to failure dropped due to the formation of dislocation substructures, decreased slowly due to the increase of dislocation density, and saturated with drawing strain. During annealing, elongation to failure increased due to recovery, and saturated with annealing time. The variation of elongation to failure in cold drawn and annealed steel wires would depend on the distribution of dislocations in lamellar ferrite. The orientation of lamellar cementite and the shape of cementite particles would become an effective factor controlling number of turns to failure in torsion of cold drawn and annealed steel wires. The orientation and shape of lamellar cementite would become microstructural features controlling reduction of area of cold drawn and annealed steel wires. The density of dislocations contributed to reduction of area to some extent.

中文翻译：

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不同拉拔应变和变形后退火条件的冷拉超共析钢丝组织与延性参数的相关性

研究了超共析珠光体钢丝的显微组织与延展性参数之间的关系，包括面积减小，断裂伸长率，分层的发生以及扭转断裂的匝数。将相变后的钢丝在620°C下进行连续干拉伸，以拉伸应变为0.40至2.38。为了检查热浸镀锌条件的影响，在盐浴中于500°C下以30–3600 s的不同加热时间对冷拔钢丝（ε= 0.99、1.59和2.38）进行了变形后退火。 。在冷拔丝中，由于位错亚结构的形成，断裂伸长率下降，由于位错密度的增加而缓慢降低，并随着拉伸应变而饱和。在退火过程中，由于恢复，断裂伸长率增加，并随着退火时间而饱和。冷拔和退火钢丝断裂伸长率的变化将取决于层状铁素体中位错的分布。层状渗碳体的取向和渗碳体颗粒的形状将成为控制冷拔和退火钢丝扭转破坏次数的有效因素。层状渗碳体的取向和形状将成为控制冷拔和退火钢丝面积减小的微观结构特征。位错的密度在一定程度上有助于减小面积。层状渗碳体的取向和渗碳体颗粒的形状将成为控制冷拔和退火钢丝扭转破坏次数的有效因素。层状渗碳体的取向和形状将成为控制冷拔和退火钢丝面积减小的微观结构特征。位错的密度在一定程度上有助于减小面积。层状渗碳体的取向和渗碳体颗粒的形状将成为控制冷拔和退火钢丝扭转破坏次数的有效因素。层状渗碳体的取向和形状将成为控制冷拔和退火钢丝面积减小的微观结构特征。位错的密度在一定程度上有助于减小面积。