Process Optimization And Numerical Analysis On Cone-Type Piercing

Piercing is the first step to produce seamless steel tubes to make the tube deformed, so the piercing technology has direct impact on the quality of half-finished steel tubes and even finished steel tubes. As the process of piercing and deformation is so complicated that the better stress analysis is too hard to do; in practical work, people select the parameters for the piercing of piercing mill mostly depending on the experience or the similar unit, so there are more difficulties to adjust the parameters, therefore we can't make sure that piercing process is in best condition. So how to select a group of parameters for the piercing process to improve piercing technology and to create better working conditions for the piercing mill are going to be of significant importance both in theories and practice.Therefore, this paper firstly selects a representative cone-type perforator of a steel tube company as reference, then makes models with Pro/Engineer software and arranges all the numerical simulation schemes for kinds of conditions with the orthogonal test method, then this paper makes 3d rigid-plastic finite element models for the piercing process with DEFORM-3D software and does finite element analog simulation. Then, this paper discusses the effects that technological parameters of piercing including top extended length of plug, rolling angle, feed angle and distance of guide plates have on the half-finished steel tube outside diameter, wall thickness, elliptical degrees, rolling force, rolling torque and mandrels axial force, then analyses the significant sequence of the effects. Then, this paper gets a group of better process parameters for the piercing with orthogonal optimization method and achieves the goal of optimizing piercing technology. Finally, this paper does finite element simulation to the piercing process of piercing mill with orthogonal optimization method, analysis pattern of metal flow, the stress and strain of tube billet, and pattern of rolling force and torque in piercing process.Compared to the practical production, the finite element simulations are more accurate and the optimizing results are more perfect. The conclusions in this paper have more guiding significance for the perforator designing, selecting of technology parameters and field production.