Groove Design And Numerical Simulation Of Bar Ferritic And Multidirectional Rolling

Compared with the ordinary bar, the ultra-fine grain bar has high strength, highhardness and toughness and other characteristics, excellent properties make it hasremarkable economic and social benefits, which caused extensive concern of all countries.There are many factors in the process of refining steel material organization, theequivalent strain and temperature are the most important factors. Manufacture below1μmultra-fine ferritic organization makes use of phase change when introduces large plasticdeformation in grain boundary appearing large angle ultra-fine equiaxial grain. But in thebar rolling how to get the groove parameters to increase strain met with obstacles.Therefore this paper proposes new groove design concept based on size and performancebothway comprehensive controlling.For low temperature ferritic region of bar rolling process parameters, using thermalsimulation experiment machine make sure typical low carbon steel(such as Q345) plasticflow curve and the thermal physical parameters, the relation between large plastic strainand ultra-fine grain distribution are researched, the relation between Zener-Hollomonfactor and the deformation metal internal organization grain size and performance arestudied.Utilization of the plastic flow curve through the experiment and three-dimensionalfinite element as tool set up the finite element model of low temperature bar rolling.Through the finite element simulation result researched the groove parameters influenceon the metal flow law of deformation area, analyzed broadsiding rule and metal fillingprofit and loss situation on groove, studied the law of groove size influence on the rolledpiece deformation penetrating to the heart, established the relation between grooveparameters and large plastic heart permeation. The grain size and deformation parametersrelationship embedded into finite element model through the finite element softwareABAQUS provides VUSDFLD subroutine, finally obtained the ferrite grain sizedistribution cloud picture. At the same time in comprehensive consideration of the shapeand size and performance used visual programming language VB development groove design system.Through finite element simulation of bar rolling can accurately know the distributionof temperature field, strain field in the rolling process. Through the physical simulationexperiment can effectively verify the condition of producing ultra-fine grain whichprovided experiment evidence for finite element simulation. For the new process of rollingultra-fine grain bar provides guidance.