Simulation And Study On The Straightening Process For 60kg/m 100-meters Heavy Rails Made Of U71Mn

Heavy rail is the most important part of the railway track,since it guides the wheel and transfers loads.With the continuous development of the speed-up and heavy-load trains,the design requirements of heavy rail are strict.As a final process of heavy rail production,straightening deformation process will affect the quality of the heavy rail.The further research on the straightening deformation process is very significant for the heave rail.In this paper,the U71 Mn 60kg/m heavy rail is taken as a research example.According to the related literature,the roller parameters such as roll distance,roll length and roll diameter are calculated for the nine-roller and the eleven-roller straightening deformation systems.Three-dimensional models of heavy rail is established using Software SolidWorks for nine-roller and the eleven-roller straightening deformation systems.Using finite element software ABAQUS,the elastic and plastic analysis model and the thermo-mechanical coupling analysis model are created for the nine-roller and the eleven-roller straightening deformation systems.The relevant distribution principles of temperature field,stress,strain are obtained.Analysis results show that:(1)In the straightening deformation process of stretching,the influence of the tensile force on the equivalent stress and the maximum strain is less than that of tensile speed for the heavy rail when the stretching time is constant.The tensile speed of the straightening deformation process of stretching should be less than 45m/min;(2)In the nine-roller and the eleven-roller straightening systems,the strain distribution principle shows that the strain is the alternated between the compressive strain and the tensile strain for the rail head.The strain is alternated between the tensile strain and the compressive strain for the rail bottom.The stress distributions of the rail head and bottom are same as those of the strain distribution;(3)Comparing the nine-roller and the eleven-roller straightening deformation systems,it is obvious that the latter is better than the former;(4)Thermo-mechanical coupling analysis results states that the highest temperature of rail head is 976 °C.There are both tensile strain and compressive strain on the rail head and rail bottom.The stress distributions of the rail head and rail bottom are same as those of strain distribution.Analysis results of this paper provide a basis for determining the reasonable straightening deformation scheme of heavy rail.They are also of theoretical significance to improve the straightening deformation quality and develop reasonable straightening deformation process for heavy rails.