Process Analysis And Optimization Design Of Radial Forging For Rectangular Cross-Section Billet

Radial forging is an advanced forming technique for bulk forging,by which material is compressed at three dimensional direction while billet cross-section is shrinking with axial direction elongation.It owns high surface quality,size accuracy,high material usage ratio and productivity.Recently,the main study for radial forging concentrates on circular cross-section,there are few researches concerned about rectangular cross-section.Radial forging of rectangular cross-section is a complicated process,which has not yet conducted process analysis by analytic model aimed at the continuous feeding forging,also not proposed the computing models to evaluate optimization objectives,such as forging load,forging quality and forging efficiency,meanwhile,there has not raised a reasonable project to plan process for radial forging.Considering such challenges,the main study of this paper focus on:Firstly,according to deformation characteristics of radial forging of continuous feeding rectangular cross-section process using finite element simulation,an upper bound model was proposed to resolve radial forging based on a hammer of forging process,which was proved by FEM results.Combined with the upper bound model,it was concluded that the decrease of reduction ratio,feed ratio,friction coefficient,reasonable mold angle would reduce forging load;meanwhile,In order to cut down spread of billet,reduction ratio and feed ratio decreased,and a method with overage compensation of reduction ratio was used to keep shape of billet;and then lower friction coefficient,higher reduction ratio and feed ratio,designing suitable mold angle would promote forging efficiency.And then,Aimed at three objectives of forging process,including forgings quality,forging load,and forging power,the prospective models were proposed,and the errors between FEM and model was under 10%.Considering deforming characteristic of radial forging,forging load model of plane deformation was applied to predicting radial forging load;The forging permeability was predicted by modified triangle rule,which extended from circular to rectangular cross-section;A predicting model of forging power is presented.Based on the proposed models,radial forging process optimization was conducted by weighting forging efficiency,forgings quality and forging load into a single objective function by fuzzy method,which took the pass,reduction rate and feed rate as optimizing parameters.At last,process optimization software was developed,meanwhile,combined experiments and FEM,process instances were conducted to validate result of craft optimization software,it had provided an evidence that such a process optimization software was applied into automatic production design of radial forging process.