捷運輕軌集電弓與導電軌國產化開發

採用歐洲系統之高雄捷運輕軌分二階段進行興建及營運，其中，輕軌二階經半年營運後即陸續發生列車集電弓出現局部熔蝕，以及部分車站導電軌鍍鎳層出現嚴重剝離及起泡問題。本研究利用破損分析解構發生異常腐蝕之原因，並依腐蝕機制提出可行的開發對策，開發國產化之高耐蝕部件。二階列車小集電弓採銅合金基材＋銀鍍層，於含硫的工業大氣環境下運行，銀鍍層易生成導電度極差之硫化銀，致使與導電軌接觸時無法形成良好之電導通，極高充電電流於接觸面形成高熱電弧，使表面發生燒熔。在導電軌部分，二階導電軌鍍鎳層雖較一階為厚，然鍍層與鋁基材界面平整，且使用後之鎳鍍層發生完整剝離，研判於二階導電軌於無電鍍鎳製程前、鋁基材表面未施以表面粗化程序，導致鍍鎳層附著性差，大氣中之Cl腐蝕因子經由鍍層孔隙進入界面處，容易與鋁基材發生氧化導致膨脹所致。小集電弓利用變更材質與機構設計優化方式，降低燒熔發生機率；而導電軌優化鍍層前製程以提升界面粗糙度，大幅提升耐氯鹽腐蝕性質，順利完成國產化部件開發。

關鍵字

捷運輕軌；集電弓熔蝕；導電軌鍍層剝離；硫化；表面粗化

並列摘要

The Kaohsiung Light Railway Transit (LRT), which adopts the European system, is being constructed and operated in two phases. After a short period of operation on the phase II, partial melted-like corrosion of the small pantograph of the train and severe peeling and blistering of the nickel-plated layer of the power rails of some stations were occurred. This study uses failure analysis to deconstruct the causes of abnormal corrosion, proposes feasible development countermeasures based on the corrosion mechanism, and develops domestic high-corrosion-resistant components. The analysis results show that the small pantograph used in the phase II train is made of copper alloy base material with silver coating. Silver react easily with sulfur into silver sulfide while operating in the sulfur-containing industrial atmosphere of Kaohsiung. Silver sulfide with extremely poor density makes it impossible to form a good electrical conduction when contacting and charging the power rail. A significant charging current generates an intense arc of high temperature on the contact area between the tiny pantograph and the power rail, resulting in surface melting. The corrosion resistance of the power trail in phase II worse than that in phase I is considered that the surface of the aluminum substrate has not been roughened before the electroless nickel plating process, resulting in poor adhesion of the nickel plating layer. It causes corrosion factors such as Cl in the atmosphere to enter the interface through the pores of the coating, and is easy to oxidize with the aluminum substrate. The materials selection and mechanism design optimization methods are used for the pantograph to reduce the probability of surface melting. The conductive rail optimizes the pre-coating process to improve the interface roughness, greatly improve the chlorine salt corrosion resistance. Thus, above two components successfully complete the development of localization.