Abstract: A frog is a key component in railway tracks. The impact load and contact stress generated when trains pass through the frog tend to cause damages such as wear, fatigue cracks, and spalling on the frog, which affect the stability and safety of the track. Research on welding repair technology for high‑manganese steel frogs helps improve the service life of frogs and the smoothness of railway lines. This paper studies the properties of deposited metals of high‑manganese steel electrodes with different chemical compositions from the aspects of materials and processes. Shielded Metal Arc Welding (SMAW) was used to repair new‑type high‑manganese steel, and mechanical property tests including tensile, impact and hardness tests, as well as microstructure characterization, were carried out on the deposited metals.
The results show that after SMAW repair of high‑manganese steel frogs, the deposited metals of both welding materials exhibit good weld formation and dense bonding with the base metal, which can be applied to the repair of frog defects and extend the service life of frogs. The deposited metal of the welding material with increased carbon content achieves a tensile strength of 785 MPa, yield strength of 472 MPa, and hardness of 209 HB, together with excellent toughness and plasticity, with an elongation after fracture of 38% and a room‑temperature impact toughness of 124.7 J. Its tensile strength reaches 79% of the base metal, yield strength 91%, and hardness 89%. Microhardness tests show a good transition between the deposited metals of the two electrodes and the base metal. EBSD results indicate that the deposited metal has a single‑phase austenitic structure. EDS line scan and mapping results reveal uniform chemical composition without obvious segregation. Increasing the carbon content of the electrode effectively improves the mechanical properties of the deposited metal. Meanwhile, the post‑weld rapid cooling process avoids the precipitation of intergranular carbides, thus obtaining a repair layer with excellent performance. The research results have important application value in the field of welding repair of high‑manganese steel frogs.