【摘要】 经冷拔变形的金属线材在抗拉强度得到大幅提高的同时,伸长率明显下降,需要采用后处理方法来实现软化。采用不同频率的高强脉冲电流对两种冷拔金属线材(镀铜焊丝和55CrSi弹簧钢)进行处理,并通过单轴拉伸和金相分析研究电流对其性能和组织的影响。与处理前的样品相比,在较低的脉冲频率作用下,高强度镀铜焊丝和55CrSi弹簧钢的显微组织均没有发生明显变化,而抗拉强度分别下降17%和16%,伸长率分别提高36%和195%;提高脉冲频率后,在二者的显微组织中开始引入细小均匀的等轴晶,而抗拉强度分别下降40%和26%,伸长率则分别提高793%和384%。与退火热处理相比,高强脉冲电流可作为一种高效快速的冷拔金属线材后处理方法。更多还原

【Abstract】 Effects of pulse frequency on mechanical properties and microstructure of two cold-drawn metallic wires(copper-coated iron wire and 55CrSi steel wire) treated by high-density pulsing current were studied by uniaxial tension and metallographic analysis.The results show that under the action of high-density current with low pulse frequency,no significant change of the microstructure is observed,and the tensile strength decreases by 17% and 16%,and the elongation increases by 36% and 195% for the copper-coated iron wire and 55CrSi steel wire,respectively.With increasing pulse frequency,fine and uniform recrystallized grains are formed,leading to the decrease of the tensile strength by 40% and 26%,and the increase of the elongation by 793% and 384% for copper-coated iron wire and 55CrSi steel wire,respectively.Therefore,the high density pulsing current treatment is an efficient post treatment process for cold-drawn metallic wires compared with isothermal annealing.更多还原