The Theoretical Research Of Rail Universal Rolling Process Deformation Mechanism And The Unit Of Pressure Distribution

The rail is the most important parts of the railroad tracks, bear the guide wheeland load transfer functions. Therefore, the importance of rail in the rail transportationis self-evident. Rail universal rolling process has a very significant impact to thefinished rail flatness, surface quality, the distribution of residual stress andmicrostructure performance, in order to obtain high-performance rail, it is verynecessary to research the rail universal rolling process of deformation mechanism andthe deformation zone pressure distribution in-depth.This paper target on the rail universal rolling process, research the rail universalrolling process between the rail head and rail waist and between the rail base and railwaist metal horizontal flow pattern, the rail head and rail base width Exhibition law,units of the vertical extension of the law of the rail at the end of the rail head and railwaist and rail waist deformation zone pressure distribution law by the analyticalmethod. Derived a more accurate elongation formula and unit pressure formula, andsimulate the rail universal rolling process to verify the formulas.First, use the " roll’s average radius" theory simplify the vertical roll with a holepattern into a flat vertical roll. Derive the formula for the area of the various parts ofthe three-dimensional deformation zone and the projected length of deformation zoneduring the rolling process. Compose the revised broadening formula and the constantvolume rule, calculate the elongation rate formula and the impacts of the various partsextension, spread and metal horizontal flow.by the different reduction rate.Second, according to the equal to the second flow principle deduced rub rollingzone of three-dimensional neutral line equation. Consider rail waist, rail head and railbase separately, listed the force balance equation of the rail head and rail base by theforce balance equations, calculate the average shear stress which rail waist acting onthe rail head and rail base on both sides. On the base of Orowan equations and theSims formula, use the average shear stress, lists the force balance differential equationof the rail waist portion, derived the unit pressure distribution formula. Finally, use the 3D modeling software SolidWorks, establish the geometric modelof billet and roll, imported on DEFORM-3D software, adopt reasonable pressurepasses as well as boundary conditions to simulate. Get the parameters of displacementfield, the metal flow field and the unit pressure for each pass, verify that the deducedelongation formula and the formula of the unit pressure.By finite element simulation results can be drawn to the results obtained by theformula in line with the actual situation of the rail scene, and thus provide theoreticalguidance for on-site production.