SIMULATION OF DIE FORMING A BALL FROM A CYLINDRICAL MAGNESIUM BILLET
In oil production, magnesium balls act as valves that temporarily lock wells and self-dissolve under the influence of drilling fluids. For the manufacture of such balls, various methods of casting, pressure treatment and cutting are used. Die stamping, which has a favorable stress state scheme, is the most suitable way to manufacture magnesium balls. The aim of the work is to simulate the stamping process of a cylindrical magnesium billet to produce a ball, as well as to assess the effect of the dimensions of the initial billet on the stress-strain state and the distribution of the temperature field of the billet during the stamping process and at the end of deformation. Analysis of the stress-strain state of the billet during ball stamping showed that the distribution of deformation and the level of its values depend on the initial dimensions of the billet. It is established that with an increase in the ratio of the height of the initial billet to its diameter, the level of the degree of deformation in the volume of the ball increases. The evaluation of the stress state indicator at the last stage of stamping made it possible to identify the dangerous zone of the billet from the position of destruction - the part of the billet adjacent to the control point P2. Here, in the process of deformation, there is no lateral support from the tool side. In addition, it was found that with an increase in the ratio of the height of the initial billet to its diameter, the stress state indicator at the control point P1 (the central part of the billet) decreases by 40 % at the last stage of stamping. Evaluation of the temperature field of the billet at the last stage of deformation allowed us to establish an increase in the temperature level in the volume of the billet with an increase in the ratio of the height of the initial billet to its diameter.