抄録
One of the limiting factors in an operation of a high-speed train is the wave propagation rate in trolley wire, because the current collecting performance is reduced when the speed of a train reaches the wave propagation rate. Therefore, an operation of a high-speed train requires trolley wire with high wave propagation rates. For this purpose, the trolley wire should be tightened up with high tension stress which in turn requires a high-strength property and/or should have less density, although the mechanical properties including wear and (corrosion) fatigue and other properties such as electric properties should be sufficient. In this investigation, fatigue and corrosion fatigue properties have been evaluated in a newly developed high-strength Cu-Sn trolley wire for an operation of a high-speed train. The influence of NaCl solution on corrosion fatigue life is found negligible, because of relief of stress concentration due to initiation of multiple cracks, blunting of corrosion fatigue crack tip by dissolution, and decrease in total crack depth due to general corrosion on the wire. Therefore, the corrosion fatigue strength is determined by mechanical fatigue strength in air. Attention is also paid to crack initiation and corrosion behavior by using scanning electron and atomic force microscopy, and the mechanisms of corrosion fatigue are discussed.
