Study of the Operating Conditions of Piercing Mill Shoes Using Computer Modeling

The operating conditions of piercing-mill shoes of “classical” configuration are discussed. The following main parameters of the shoe configuration affecting the sticking of metal of the hollow shell to the shoes are determined: the length of the cylindrical section of the shoes, its location relative to the axis of the piercing mill, the taper angle of the exit section, the radius of the groove of the shoes, the ovality in the deformation zone. Computer modeling with increasing and decreasing the parameters of the shoes was carried out using QForm 2D/3D software. Of the results obtained, the following parameters of the piercing process that indicate the tendency to the sticking of the metal of the hollow shell to the shoes were selected: the forces acting on the working surface of the shoes during piercing, the time of contact between the shoes and the hollow shell, the contact area, the temperature of the working surface of the shoes during piercing. Procedures for assessing the resistance of the shoes to the sticking of metal of the hollow shell during piercing are proposed. Three alternatives of shoes with reduced tendency to sticking of the metal of the hollow shell are developed by analyzing the modeling results using these procedures. The most promising shoe configuration was determined using computer modeling.