Research On Local Forging Process Of High Manganese Steel Frog

The frog is a crucial component in railway tracks and an important part of the railway system.Due to the complex terrain and harsh environment of the Qinghai-Tibet Railway,frog maintenance is extremely difficult,which has led to higher demands for the quality of high manganese steel frogs.As the working surface of trains,the frog’s point rail and wing rail are subjected to complex mechanical forces and are often prone to defects such as stripping and chipping due to wear,especially in the thinnest areas of the frog.Currently,mass-produced high manganese steel frogs are cast,but casting itself has limitations that often result in casting defects such as shrinkage holes,shrinkage cavities,non-metallic inclusions,etc.,which affect the service life of high manganese steel frogs.In contrast,forging can effectively close shrinkage holes in cast high manganese steel frogs,refine grain structure,and improve the mechanical properties of frogs.However,due to the complex structure of the frog,overall forging is challenging,meaning that it is essential to study a process for local forging of the weak areas of the frog to enhance its mechanical performance and extend its service life,with significant engineering significance.In this paper,taking the 75kg/m rail No.12 frog of the high manganese steel as the research object,the thermal deformation behavior of the high manganese steel material is analyzed,and the two-dimensional and three-dimensional finite element models of the partial forging process of the frog of the high manganese steel are established,and the forming characteristics of the partial forging of the frog are analyzed.The results show that the axial direction of the frog is bent,and the wing rail is bent longitudinally during the forging process.The bending defect of the small section of the wing rail is the most obvious.In addition,the strain distribution of the frog center rail and the wing rail is similar.The strain in the center area is larger,and gradually decreases along the center.Dead zone exists at the top of the frog center rail and the wing rail.The effect of die structure,blank shape and process parameters on the forming quality of the frog is also studied,and the optimal process of the frog of high manganese steel is determined.The results show that proper upper cavity structure is beneficial to reduce the defect of wing rail bending.The axial bending of the frog can be reduced effectively by extending the length of the lower die properly.The circular top blank can effectively reduce the dead zone of the frog tip.The larger the compression ratio,the larger the strain of the core rail(wing rail).The smaller the inclination of the core rail(wing rail)billet,the more uniform the strain distribution.The increase of mold temperature can effectively increase the surface temperature of the frog.The pressure velocity is negatively correlated with the strain of the frog and positively correlated with the surface temperature of the frog.The effect of pressing speed on forming force of upper die is obvious.Finally,the partial forging die and blank of the frog of the high manganese steel are designed in equal proportion,and the forming experiment of the frog of the high manganese steel is carried out.The feasibility of the designed partial forging process is verified by the field experiment.