Research On The High Temperature Constitutive Model Of300M Ultrahigh Strength Steel

With the innovation of technology, physical simulation and numericalsimulation technology have been widely used in various research fields, and theprecision of the simulation depends on the material constitutive model, therefore,the material constitutive relationship has always been a hotspot in research ofmaterials and mechanics.300M ultrahigh strength steel has good comprehensivemechanical properties, is widely used in aircraft bearing components. In thisthesis, it is research the constitutive model of hot deformation and theconstitutive model of metal cutting deformation of300M steel. The maincontents of this thesis include:First, through high temperature compression test in thermal simulationtesting machine, get the stress-strain curve of300M steel within the certaindeformation conditions scope, analysis the effect of different hot deformationparameters on the flow stress combining with the test results, the results showthat under the condition of the strain rate is constant, with the increase oftemperature, flow stress significantly reduced； in under the condition ofconstant temperature, along with the increase of strain and the rate flow stressincreased.Second, on the basis of the data of high temperature hot compression test,research the constitutive model of hot deformation, using two kinds of methodwhich is Arrhenius equation and BP neural network, respectively set up the hotdeformation constitutive model of300M steel, to describe the relationship offlow stress with the strain rate and deformation temperature. By the predictingvalue of rheological stress and its variation trend, analyze and evaluate two kindsof model, and point out the merit and demerit of the two models.Finally, analyze and point out that the constitutive model of hot deformation cannot be applied to metal cutting, combining with the existing cuttingdeformation constitutive equation and experimental method, based on theexperiment purpose and the existing experimental condition, adopt the method ofcutting experiments and theory analysis, determine the modeling course ofsolving Johnson-Cook model, through the quasi-static compression experimentand orthogonal cutting experiment, deal with the experimental data, get the valueof the five factor of the Johnson-Cook constitutive relation, thus get theJohnson-Cook constitutive relation equation of300M steel. And based onAdvantEdge FEM software, import the Johnson-Cook constitutive relation,simulate the orthogonal cutting process, through the simulation results to verifythe accuracy of the constitutive model.