Electric Arc Surfacing of Defective Plots of Rails in the Area of Electrocontact Welded Joint

摘要

One of the main causes for the failure of the rails of a continuous joint made by electric contact welding is defects in collapse and wear in the joint zone. We address the usage of electric arc surfacing to repair defective rails. The structure and hardness are studied of the defective areas of rails recovered by electric arc surfacing performed in one and two layers. Static tests and fatigue tests of pilot samples of rails with eliminated defects were carried out. The pilot samples with defects eliminated by electric arc surfacing meet the criteria of static strength to the same degree as the rail samples without surfacing. The surfacing technology that we examined should be adjusted by applying preheating to reduce the cooling rate of metal in the weld zone. Fatigue tests showed a positive effect from surfacing at the wear sites in the welded joint. Performance tests confirm that electric arc surfacing is promising to eliminate defects in the collapse and wear of the rails in the area of the electric contact welded joint.