Study Of Steel Tube Precision Drawing Technology With Internal And External High Pressure Lubrication

Because of the good comprehensive properties, cold drawn tubes which are cal led “industrial blood vessels” are widely used in the industry. However, the tubes u sed in the high-tech products are different from the normal ones owing to the high er accuracy and better surface quality. The tube produced by traditional drawing tec hnology is difficult to achieve request of the precision tube. In order to meet the r equirement, the tubes are still grinded and polished after drawing. Short mandrel tu be drawing process is employed for producing high precision tube for the inner pi pe diameter size and surface quality. However, the poor lubrication cooling proble m between the mandrel and inner pipe surface made it difficult to produce qualifie d products. Study of steel tube precision drawing technology with internal and exter nal high pressure lubricationis an innovative based on short mandrel drawing techn ology. It used boundary lubrication to reduce the effect of friction on the drawing process and drawing force. What’s more,boundary lubrication has good heat dissip ation,so that these advantages would improve the precision of cold drawn tube. Thi s paper mainly studied included below: 1.The paper established the calculation formula of drawing force took liquid pre ssure in thesealing cylinders into consideration under internal and external high pre ssure lubrication; 2.Tube necking forming process was simulated with non-linear F EM programme MSC.Marc to analysys necking forming limit and influence that w as caused by different ratio of thickness to diameter. Finally, we studied regularity of stress distribution and the influence of process parameters on the necking force;3.Non-linear FEM programme MSC.Marc was employed for simulating drawing pro cess to explore regularity of the axial stress, radial stress, shear stress, Mises stres s. Besides, we compared simulation and calculated values of the axial stress by an alysising the influence of cylinder pressure seal on axial stress, to verify the accur acy of the formula of the drawing force; 4.The paper studied the mainly influent f actors on the drawing force, such as friction coefficient, modular angle, drawing velocity, contraction ratio of section and liquid pressure of the sealing cylinder, espe cially modular angle about which we gave out the best modular angle for the mini mum drawing force by analysising simulation results, and we studied the limits of the pipe cross-section contraction; 5.The paper putted forward to the solving measu res by analysising the actual problems which production encountered. The above stu dy results can provide theoretical support and technical guidance for the actual pro blems which production encountered.