| The world's railway is developing towards the trend of High-speed and heavy-haul,and it puts forward higher requirements on the mechanical properties of the seamless rail.The welded joints of rail is the main weak link of seamless line,which can easily occur abrasion,brittle fracture and collapse.In our country,most of the welded joints are welded by flash welding technology.It is of great significance to study the flash welding process and optimize the welding parameters,in order to improve quality of welded joints.In this paper,the 60kg/m U75V hot rolled rail welded joint is object of study,and based on the finite element software ANSYS,the numerical simulation of welding process is studied.In addition,the mechanical properties,hardness and microstructure of the welded joint were compared and analyzed with base metal.The main research contents and conclusions are as follows:(1)The finite element model of rail flash welding is established,this paper uses"life and death" technique to simulates the burning process of material.(2)The temperature field of flash welding and cooling process is simulated.The paper analyses temperature variation of different parts and the influence of different technological parameters on the temperature field,which provides a reference for the actual flash welding process.(3)The indirect coupling method is used to calculate the stress distribution of cooling process,the stress distribution of different parts is analysed.(4)The base metal and welded joints were subjected to tensile,impact,hardness and microscopic observation.The comparison and analysis of the experimental results were made.The simulated temperature field was verified by infrared thermometer,the actual temperature matched well with the results of the numerical simulation,which proved the finite element simulation is feasible. |
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