Description

Railway crossing usually bears enormous impact force and rolling contact stress during service, resulting in various surface defects or even failure of the wing rail. In this paper, to achieve “green” and sustainable development, the U75V pearlite rails, widely used in the cross wing rails, were repaired by laser cladding 17-4PH precipitation hardening stainless steel on the rail surface. The microstructure evolution and their effects on the mechanical properties and wear properties of the repaired rails were systematically investigated. As a result, the repaired region is mainly composed of lath martensite, retained austenite, ?-ferrite and some carbides. The mechanical properties of pearlite wing rail can be enhanced by depositing 17-4PH coating using laser cladding process, in which the yield strength and impact toughness is increased to 1.1 times and 7.3 times, respectively. Besides, the wear resistance of the repaired wing rail is enhanced to 2.1 times as much as those of the untreated rail. The coating possesses high yield strength due to the high-alloyed solution strengthening and precipitation strengthening, while the massive austenite allows the coating to maintain the excellent work-hardenability, which ensures the good wear resistance of repaired pearlite wing rail. Therefore, all findings reveal that 17-4PH is the promising cladding material for repairing the U75V pearlite wing rails by laser cladding.

Contributing Authors

  • Beibei Zhu
    Huazhong University of Science and Technology
  • Xiaoyan Zeng
    Huazhong University of Science and Technology
  • Qianwu Hu
    Huazhong University of Science and Technology
Beibei Zhu
Huazhong University of Science and Technology
Track: Laser Materials Macroprocessing
Session: Poster Gallery
Day of Week: Tuesday
Date/Time:
Location: Exhibit Hall

Keywords

  • Laser Cladding
  • Mechanical Properties
  • Microstructure
  • U75V Pearlite Wing Rail
  • Wear Properties