| This paper describes the bending fatigue properties of the high-carbon steel wire containing around 0.6 wt.% C, which is used as a stranded wire for ACSR(Aluminum Stranded Conductors Steel Reinforced) in transmission power lines. ACSR which consists of galvanized steel strand and aluminum one always experiences serious vibration by wind. Therefore, it is very important to clarify the fatigue property of core wire for ACSR to determine its lifetime and stability of power delivery. Since steel wires are produced by wire drawing process, they possess a very long fiber lamellar microstructure which has a very short inter-layer distance between ferrite and cementite layer. The long fiber lamellar microstructure is expected to have a different fatigue behavior compared to conventional plate and bulk-type materials. In order to characterize the fatigue property of cold-drawn high-carbon steel wires, bending fatigue tests were carried out on specimens drawn to various strains. The fatigue strength was about 38 kgf/㎟ at ε= 1.19, which was higher than the required strength of 32 kgf/㎟. This is probably due to the very fine elongated pearlitic microstructure formed by the drawing process, which suppresses formation and growth of microcracks. The several unique characteristics of drawn wires are also discussed. |
|
