Stress Analysis And Research Of Fatigue Life Of The Continuous Extrusion Wheel

Traditional extrusion method works intermittently. There exists many problems such as large energy consumption, poor product uniformity and so on.1970s, D.Green worked in British Atomic Energy Agency (UKAEA) invented the continuous extrusion forming technology (CONFORM). This technology makes continuously work possible, improves the material utilization rate effectively, the quality of products and reduces energy consumption.Extrusion wheel is an important part of continuous extrusion machine and forms extrusion cavity with groove block. Metal move along the cavity and deform gradually driven by the friction force of extrusion wheel. Eventually, metal extruded out of die hole. The working condition of extrusion wheel is poor. Friction between metal and wheel causes increase of temperature and high stress. The service life of extrusion wheel restricts the production efficiency of continuous extrusion. Improvement of service life of extrusion wheel can reduce production costs, improve efficiency and produce huge economic benefits.In this paper, optimization direction of extrusion wheel is determined according to sample analysis. And research of the effect of surfacing material and thickness of surfacing layer is carried out with finite element analysis using ANSYS.Firstly, the H13 extrusion wheel specimens are tested with fluorescence spectrum analysis, optical microscope, universal electronic testing machine, etc. Chemical composite, microstructure, mechanical properties at room temperature and high temperature are tested. Results show that high stress and deformation concentrate on the end of extrusion wheel working area. The deformation direction of working area is opposite to the deformation direction of non-working area. The bottom of wheel groove is subjected to alternating load, which forms fatigue crack easily. The FEA results match practical cases.Secondly, Stress, deformation and fatigue damage of nickel base alloy surfacing and D397 surfacing extrusion wheel are simulated using the finite element model mentioned above. Compared the result of surfacing extrusion wheel and H13 extrusion wheel, D397 surfacing electrode is selected as the surfacing material.Finally, stress, deformation and fatigue damage extrusion wheel with different surfacing layer thickness are simulated. The results show that with the rising of the surfacing layer thickness, extrusion wheel fatigue life increases firstly and then decreases. The appropriate thickness is 8 mm.