CAE Analysis Of The Large-Gram Steel Balance Weight At Warm Temperature And Plastic Forming

The wheel balance weight place on the wheel rim,which plays positive role atmaintaining security and stability while cars are running rapidly. Accompany with theupsurge of the global economy development, auto industry also follows a high speedperiod of development. As one of automobile parts, the demand for wheel balance weightis also increasing year by year. In the early period,the wheel balance weight is mainlymade of lead, to be in accordance with environmental guidelines in recent years, manybusinesses substitute steel for lead. Specification of wheel balance weight is between5gand300g, the one for small cargo is between5g and50g,cold plastic forming process canbe used; but for commercial vehicle, like heavy truck,its wheel balance weight is morethan60g, which is hard to be formed by common cold plastic forming process. In thispaper,warm-plastic forming process is used to solve this problem,Q235steel is taken asthe subjects and100g balance weight is regarded as carrier,the association method ofactual physical test and numerical simulation is taken to analyse and research warm-plasticforming property of Q235steel,as well as wear failure of bottom die for wheel balanceweight in forming. The chief research contents of paper are divided into three parts.The first part is the mechanical properties study of warm-plastic forming on Q235steel.True stress-strain curves have been gained by compressive deformation of Q235steel,which was carried out with Gleeble-3500heat simulating apparatus over the range ofdeformation temperature from500℃to900℃, strain rate from0.1s-1to10s-1; themechanical constitutive relations of Q235steel is described based on Arrhenius hyperbolicsineequation, and the deformation activation energy of Q235steel is274.4902kJ/mol;build the BP network in Matlab softwares to forecast the stress vaule on strainpredetermined, finally setup the Q235steel material model in Deform software to call it insequent numerical simulation. The second part is warm-plastic forming simulation of100g-Q235steel wheelbalance weight with different technological parameters. To be specific, differentcombination of technological parameters include velocity of top die、 temperature ofblank、 friction coefficient. At every stage of formingthe steel flow、temperature filed andstress-strain field are analyzed. The best warm-plastic forming process combination ofbalance weight are: blank temperature is750℃,velocity of top die is10mm/s, lowfriction index by using high-quality lubricant after an overall consideration of top die’ sload、part size and surface quality.The third part is wear failure analysis of bottom die cavity. Based on the computationmodel of modified Archard Formula, take a simulation respectively on three differentprocess parameters,that is velocity of top die、friction coefficient and die hardness, to studytheir influence on wear of bottom die cavity by single process and multiple process.Law ofwear has been summarized, and the die life can be estimated by ensuring the worst wearingposition in bottom die cavity.