A numerical model was established to calculate the cycle feed rate through studying the case of a cold pilger mill with the 304 stainless steel pipe. Firstly, the precise constitutive equation of 304 stainless steel w...A numerical model was established to calculate the cycle feed rate through studying the case of a cold pilger mill with the 304 stainless steel pipe. Firstly, the precise constitutive equation of 304 stainless steel was obtained through nonlinearly fitting the true stress-strain data from unidirectional tensile test. Then, the numerical method to calculate the equivalent deformation was determined according to the plastic deformation feature of the steel tube during cold rolling and the incremental theory. Finally, the cycle feed rate of cold roiled 304 stainless steel pipe was extracted when formulating springback through utilizing above results comprehensively and unloading law. Stress state, metal flow, finished pipe size and distribution of residual stress were obtained by finite element method to calculate the whole rolling process when the cycle feed rate was 10 mm, and the optimized model was verified through finished pipe size.展开更多
As the process parameters of pilger cold-rolled seamless steel tubes are basically based on experience leading to the generation of defects, 304 stainless steel was chosen and the important process parameters includin...As the process parameters of pilger cold-rolled seamless steel tubes are basically based on experience leading to the generation of defects, 304 stainless steel was chosen and the important process parameters including the feed, rotation angle and Q value (the ratio of the length of the deformation section to that of the finishing section) were selected to analyze the effect of different process parameters on the tube forming process and rules. The results show that during the cold rolling process, the rolling force, the equivalent stress of the tube, the residual stress and the springback of the external diameter increased with the increase in the feed rate and the rotation angle and the decrease in Q value. Increasing the feed quantity and decreasing Q value will lead to the decrement in the roundness of the pipe. After comprehensive evaluation of the advantages and disadvantages, a set of optimal parameters are selected to carry out the experiment. The residual stress and the outer diameter of the finished products were measured. The results of the measurement and the numerical simulation results are within reasonable range, and the accuracy of the numerical simulations and the influence of the process parameters on the pilger cold rolling are further verified.展开更多
基金The authors are grateful for the financial assis- tance from the National Science Foundation of China （U1710113）, the China Postdoctoral Science Foundation （2017M622903）, the Fund for Shanxi Key Subjects Construction, Excellent innovation projects of graduate students in Shanxi （2017SY077）, Heavy Machinery Engineering Research Center of Ministry of Education （20172004）.
文摘A numerical model was established to calculate the cycle feed rate through studying the case of a cold pilger mill with the 304 stainless steel pipe. Firstly, the precise constitutive equation of 304 stainless steel was obtained through nonlinearly fitting the true stress-strain data from unidirectional tensile test. Then, the numerical method to calculate the equivalent deformation was determined according to the plastic deformation feature of the steel tube during cold rolling and the incremental theory. Finally, the cycle feed rate of cold roiled 304 stainless steel pipe was extracted when formulating springback through utilizing above results comprehensively and unloading law. Stress state, metal flow, finished pipe size and distribution of residual stress were obtained by finite element method to calculate the whole rolling process when the cycle feed rate was 10 mm, and the optimized model was verified through finished pipe size.
基金the National Natural Science Foundation of China(Grant No.U1710113)the China Postdoctoral Science Foundation(Grant No.2017M622903)+2 种基金the National Key Research and Development Program of Shanxi Province(Grant No.201703D121008)the Project of Excellent Graduate Innovation in Shanxi(Grant No.2017SY077)the Graduate Innovation Funding Scheme for Heavy Machinery”(Grant Nos.20172001 and 20172004)for financial support and authorization to publish this work.
文摘As the process parameters of pilger cold-rolled seamless steel tubes are basically based on experience leading to the generation of defects, 304 stainless steel was chosen and the important process parameters including the feed, rotation angle and Q value (the ratio of the length of the deformation section to that of the finishing section) were selected to analyze the effect of different process parameters on the tube forming process and rules. The results show that during the cold rolling process, the rolling force, the equivalent stress of the tube, the residual stress and the springback of the external diameter increased with the increase in the feed rate and the rotation angle and the decrease in Q value. Increasing the feed quantity and decreasing Q value will lead to the decrement in the roundness of the pipe. After comprehensive evaluation of the advantages and disadvantages, a set of optimal parameters are selected to carry out the experiment. The residual stress and the outer diameter of the finished products were measured. The results of the measurement and the numerical simulation results are within reasonable range, and the accuracy of the numerical simulations and the influence of the process parameters on the pilger cold rolling are further verified.
