Rail steel defects can lead to very expensive and time-consuming total rail replacement maintenance operations. Laser cladding repair of rail defects is a potential solution for on-site track repair applications. Reliability test trials at the Bishan Depot test track has demonstrated the concept. AFM has been approved for Main-line track tests. Development of an on-track portable laser cladding system is in progress. Laser cladding repair capability is needed to mitigate some total rail replacement maintenance for example localized defects and wear at the crossing nose and rail heads.
Cladding repair studies on the crossing nose are shown below. Hardness and microstructure studies were performed on the cladded specimen. Microscopic examination shows there are no void in the clad and interface of the clad and base material. A Singapore Provisional Patent has been filed for a portable laser cladding repair system to be developed for on-site rail steel repair applications targeted at high value on-site rail steel repairs for crossings and switches.