Study Of ZK60 Magnesium Alloy Tube Push Rolling Process And Its Forming Process

Push rolling process is a short process,high productivity and high yield pipe rolling process,the current industry in the preparation of common tube preparation process in the field of magnesium alloy tube preparation there are many drawbacks,such as conventional rolling process,rolling process is too long,magnesium alloy tube in the rolling process temperature drop faster,resulting in material plasticity decline,the rolling process is difficult to carry out;and the traditional extrusion process is slightly more difficult to prepare thin-walled tubes The traditional extrusion process in the preparation of thin-walled tubes is also slightly strenuous,and drawing process which is low-efficiency and has high tool loss or high processing cost.In this paper,based on ZK60 magnesium alloy material,a high-strength thin-walled tube was prepared by push rolling process,and the specific research contents are as follows.(1)Through theoretical analysis,the parameters related to the deformation zone of push rolling are calculated,and the forces on the mandrel and rolls during rolling are analyzed.According to the analysis results and combined with the process requirements for the hole parameters,hole distribution calculation,and according to the calculation results and field requirements to complete the design and calibration of the push rolling die.(2)Based on ABAQUS explicit kinetic finite element simulation software,the numerical simulation of the push-rolling process of magnesium alloy tubes explored the trends of tube strain,stress and temperature at different press-down rates and different process parameters,and the simulation results according to different process parameters(push-rolling speed and push-rolling temperature)showed that the increase of push-rolling speed and push-rolling temperature would reduce the residual stress of the tube billet and increase the equivalent plastic strain of the tube billet.However,too high parameters will have a negative impact on the billet forming.(3)Complete the billet push-rolling experiment and analyze the experimental results: with the increase of the billet pressing rate,the microstructure is obviously refined and the mechanical properties are significantly improved,while with the increase of the pressing rate,the number of twins increases and the elongation decreases,which weakens the plasticity of the material;with the increase of the push-rolling temperature,the uniformity of the pipe organization is improved and the twins are obviously reduced,but the average grain size changes are small and the strength is not significantly improved.However,the change of average grain size is small and the increase of strength is not obvious.(4)After the push-rolling experiment with 15% depression rate,the tensile strength of the pipe is 295 MPa and elongation is 25%;at 25% depression rate,the tensile strength of the pipe is 310 MPa and elongation is 18%;when the depression rate increases to 34.5%,the tensile strength of the pipe is 348 MPa and elongation is 14%;when 45% depression rate is reached,the tensile strength of the pipe increases to 377 MPa and elongation of 10%.(5)By observing the macroscopic morphology of the tubes after rolling at different pushing and rolling temperatures,it is found that the surface quality of the tubes is the best when the pushing and rolling temperature is 350?.