Research And Realization Of The Key Technology In The Hot Extrusion Of Pipe Material Shaping

By the simulation of metal deforming, the die with optimized parameter and the product with high quality could be got at lower cost in short period. The entire process of metal deforming could be described. Many facters should be considered and corresponded, such as material, die size, friction, temperature, speed of extrusion and the heat up length of blank, in a successful simulation of metal deforming.It was a new technics that axle-pipe accessory was got by the shrinking of pipe material, with the process of hot extrusion, the productivity could be improved evidently and the cost could be down. The benefit of economy is immense. Behind bridge of automobile, is a typical axle-pipe accessory. The manufacture method of behind bride could be improved with the technology mentioned above. Based on the analyzing of the domestic and foreign research status, two aspect, theoretic formula and finite element method of metal deforming and the coupling calculation with thermal structure., were analyzed. Some mathematic processing.methods were used in the research. The main research works are as follows:(1) The flow stress, strain characters and their sensitivity to temperature was analyzed. According to the material library data in Deform software, the multiple linear regression method was used to do the numerical fitting of the metal material in high temperature. The limitation of the simulation calculation with insufficient material method could be avoided and more accuracy result could be got.(2) Based on the characteristics of shrinking pipe material, two basic models were set up. ANSYS/LS_DYNA was used in the research, In the text, the affection to extrusion force of the parameters such as extrusion temperature, extrusion speed, coefficient of friction and mould angle were analyzed with two mould mentioned above, and a suitable revising formula was put forward for hot extrusion force of pipe material. The formula was validated by many simulation experiment, especially effective in the situation that the angle of the model was greater than 80.(3) Some manufacture factors such as extrusion speed, friction coefficient and the temperature of blank were analyzed for the metal deforming effect of shrinking pipe material,Deforming quality formula was set up via analyzing abundance experiment data. Therefore we could forecast the quality of shrinking pipe material and the trial-manufacture could be reduced, the development period could be shorten.(4) The figuration of automobile behind bridge was simulated by two-step deforming technology. The influence of the figuration and the thick of the blank were analyzed from two factors ,the length of blank heat up and the lubrication condition. Practicability of the extrusion force formula of pipe material in chapter4 and the effect of shaping be forecast in chapter 5 were both validated, and the results were favorable.