Study On Design And Analysis Method Of Ultra-High Pressure Hydrostatic Extrusion Container And Sealing Performance

Hydrostatic extrusion has the advantages of small extrusion pressure,less die wear,uniform material deformation,high dimensional precision of extruded products,smooth surface,etc.It is widely used in extrusion processing of different profiles,high temperature alloys,difficult to process materials,etc.However,ultra-high pressure(>1000MPa)extrusion is the main means to process refractory alloys such as tungsten alloy.Combining the two methods,ultra-high pressure hydrostatic extrusion is an effective way to produce high-quality refractory alloy extrusion parts.There is less production application on ultrahigh hydrostatic extrusion at present,which mainly subject to the container and the design mechanism of ultra-high pressure and ultra-high pressure hydrostatic extrusion of the sealing technology research is very limited.In a word,ultrahigh pressure container design analysis system research method,comparison analysis of super high pressure container design and structure,prediction method of the ultrahigh pressure container fatigue life,the seal performance of ultrahigh pressure hydrostatic extrusion are key technologies for the popularization and application of ultrahigh hydrostatic extrusion technology,which has great theoretical guiding significance and practical value.The main research contents of this paper are as follows:(1)The mechanical model of extrusion container is studied.The mechanical model of multilayer combined extrusion container and wire winding extrusion container is established and compared with finite element simulation and existing experimental cases to provide theoretical support for the selection of ultra-high pressure extrusion container.(2)The comparison of ultrahigh pressure extrusion structure and the analysis of structure form are carried out.Based on the mechanical model,the mathematical optimization model is established and the ultimate bearing capacity of each scheme is compared.At the same time,the winding mode and the number of layers of the core container are compared and analyzed,which provides a theoretical basis for the parameter design of the steel wire wound extruding container.(3)The service life of ultra-high pressure extrusion container is studied.Firstly,the design parameters of a set of steel wire wound extrusion container with a bearing capacity of 1500 Mpa are determined and the stress distribution rules during the extruder process are analyzed.The strain-life curve is obtained by processing the fatigue test data of the material,and the service life of the extrusion container is evaluated based on the linear fatigue cumulative damage theory.(4)A typical ultra-high pressure hydrostatic extrusion sealing structure is studied.Introduce elastohydrodynamic lubrication theory and Westeneng surface contact model,as well as numerical simulation technology.Based on the results of finite element simulation,the leakage rate and the viscous friction force are calculated and analyzed.In this paper,the selection of design scheme and service life prediction of ultra-high pressure extrusion container and the performance of ultra-high pressure hydrostatic extrusion seal are analyzed and evaluated by means of theoretical analysis and numerical simulation.