Finite Element Simulation And Analysis On BD1Rolling Process Of U71Mn Heavy Rail Steel

With the rapid development of domestic and international high-speed railtechnology, to product the the high-speed rail of "high-speed, heavy-duty, long-length,high-precision," has become inevitable.The production of heavy rail is a complex ofhigh temperature,dynamic and transient process, the rolling process parameters of heavyrail has a significant impact for organization, performance, and dimensional accuracy.Inthis paper, Based on a large steel plant BD1reversible rolling mill, The whole processof60kg/mU71Mn heavy rail slab from out furnace then high pressure water descalingto BD1blooming until BD2entry was simulated by using nonlinear finite elementsoftware ANSYS/LS-DYNA. H/V alternatively arrangement of BD1reversible rollingmill was apllied to achieve the tilting passes, which ensured the accuracy of the datatransmission.It can provide the theoretical basis for calculation of force parameters andoptimization of heavy rail pass.With simulation of changing the heating temperature and the rolling reduction ofeach pass，achieve to the temperature curve of the surface points of U71Mn heavy railsteel,the rolling pressure curves and the filling situation of pass. Results showed that thetemperature and rolling force results were in good agreement with the measuredvalues;the filling situation of every pass is better,every pass of the rolled piece side aappeared a certain degree of overlap of slab;the rolling deformaion can’t go deep intothe heart, the surface layer of metal flow layer is faster than the center;the section ofmetal particle of slab is no longer in the same plane;appropriately reduce the heatingtemperature of rolled piece does not have a major impact;Appropriately increase thereduction can reduce the BD1export section, it’s helpful to reduce the unevendeformation when the rolled piece in BD2heterotypic hole rolling,thus improve thequality of heavy rail. Simulation for different process parameters on the deformation ofrolled piece area and the equivalent stress, equivalent strain distribution in the crosssection of the export and the results showed that: the surface and the core of the rolledpiece of equivalent stress and strain distribution have differences and the equivalentstress of rounded corners have big change among each pass;the fifth pass exit sectionside have the biggest stress which is corresponding to the rail head, and the sectionstrain is uniform, it can improve the yield stress of rail head and the service life of heavy rail; when decreaseing heating temperature and increasing the rolling reduction of eachpass, the equivalent stress and strain increases accordingly.