Research On Rolling Forming Technology Of Mineral Insulated Cable

With the continuous development of China’s socialist modernization,the construction field and aerospace and other fields have been greatly developed,the requirements for wire and cable are becoming higher and higher,and the traditional wire and cable due to small load,fire,poor corrosion resistance performance can not meet the requirements of these important fields.Because mineral insulated cable as a fireproof cable has superior performance,with fire,explosion-proof,waterproof,corrosion resistance,large load and other advantages,is widely used in production and construction of important parts.However,the mineral insulated cable is a composite structure composed of powder and copper,and the general rolling process lacks the corresponding theoretical support.The trial-and-error method is usually used in the rolling process of new products,which not only causes the waste of resources,but also leads to the low precision of rolled products.In order to solve this problem,rolling high precision mineral insulated cable finished products,this paper will combine the rolling theory,in-depth study of the deformation of mineral insulated cable in the rolling process,accurate prediction of mineral insulated cable finished product size,establish the relevant mineral insulated cable rolling model.The main contents and conclusions of this paper are as follows.(1)Based on the rolling theory,the rolling models of oval pass and circular pass mineral insulated cable were established,and the ABAQUS finite element software was used to simulate the rolling models.The rolling models were analyzed from the aspects of stress,wall thickness and relative density,and the corresponding roll pass was selected based on the analysis results.The results show that compared with the round pass,the mineral insulated cable has more contact with the pass ridge area in the oval pass roll,and is subjected to greater stress,better rolling effect,higher elongation,higher density of magnesium oxide,and uniform distribution of copper coat wall thickness.(2)An initial calculation model of rolling force,wall thickness and elongation of mineral insulated cable copper coat was established by combining the rolling theory and characteristics of pipe and bar and increasing the proportional coefficient of contact area.The ABAQUS finite element software was used for simulation to obtain the corresponding function relationship,and the proportional coefficient of contact area was determined by fitting data points.By comparing the initial calculation model with the simulation results,the iterative method is used to revise the initial calculation model of copper coat,and the revised calculation model of rolling force,wall thickness and elongation of mineral insulated cable copper coat is obtained.(3)Based on the two-high rolling mill,the rolling experiment was carried out and compared with the modified calculation model and the finite element simulation results.The results show that the average error of rolling force,wall thickness and elongation of copper coat is 13.8%,0.9% and 5.28% respectively.The average error of mg O wall thickness is 5.3%,and the average error of elongation is 3.8%.The average error of copper core diameter is 5.7%,and the average error of elongation is 17.4%,both of which are within reasonable range.