Deformation Mechanism Based On The Universal Rolling Method Rail And Rolling

Rail transportation develops more and more rapidly around the worldbecause of its fast, safe, energy-saving, heavy volume and environmentalprotection. Currently the development of the railway turns toward the highspeed and heavy load, so the demands are very strict to the rail. To developnew rail steel, reasonable production technology and to promote quality andservice life have been the goal of rail production.The geometric shape size, straightness and residual stresses directlyaffect the service performance of rail. The universal continuous rollingprocess of rail is finish rolling part of the rolling process. It plays a decisivefunction on the geometric shape size, straightness and the magnitude ofresidual stresses. In this paper，the heavy rail of60kg/m was taken as anobject of study, the material parameters of U75V in different conditions wereobtained by the Gleeble-1500D simulator. The basis of paper iselastic-plasticity finite element method of large deformation, so making useof explicit dynamics finite element software ABAQUS to build upthree-dimensional FEM of heavy rail universal continuous rolling. Thedeformation law, the distribution law of stress and strain in each pass of finish rolling and the tension variation law between stands in the universalcontinuous rolling process were analyzed too.The calculation results show that under the condition of universalcontinuous rolling between UR stand and ER stand, the width variation ofrail base and rail head and the variation of rail height after UR1pass areproportional to additional tension, especially the width variation of rail baseis most obvious. ER process of edge roller and UR process of universal rollerare different; especially the variation of rail height is most obvious. Underthe condition of universal continuous rolling of UR-EF-UF standers, theinfluences of variation of speed unbalance rates of present process on thedeformation of the process of the rail are obvious. While the influences ofvariation of the former speed unbalance rates or the latter on the deformationof present process of rail are not obvious. The field measurement andsimulative calculation results show that the tension between UR3processand EF process is micro crushing stress, while the tension between EFprocess and UF process is micro pulling stress.This rule is in accordancewith actual production. Residual stress of finishing rolling of rail is from-82.6MPa to61.2MPa. Dimensional precision is controlled in the range ofGB, so the problems of universal tension in continuous rolling and controlling of dimensional precision of mill bar are explained well, andmakes the tension which comes from anisomerous and continuous rollingmill meet the demands of Non-Loop and tensionless controlled rolling.According to comparing and analyzing geometric shape size andtension between stands and field actual measurement and simulationcalculation, we prove the correctness of FEM simulation method. Finally thispaper obtains that calculation result by the model accords with actual state ofrail field and it offers theory direction for controlling of dimensionalprecision of CCS flight crew of100-metre steel rail in universal tensioncontinuous rolling.