RATIONAL FOR REHEATING IN THE AUTOMATED LINE FOR RING BLANKS PRODUCTION

Features and requirements to the use of reheating of ring blanks in the conditions of production on the automated line are considered. An assessment is given for a technological temperature state of ring blanks at various stages of production under conditions of the automated line. For assessment of rational for reheating at production of ring blanks, a classification of ring manufacturing technology is proposed with the production of a pressed non-core blank in an open die, with the production of a pressed profile blank in a closed die, with the production of a pressed profile blank in a stamp with reverse extrusion. The technology of ring rolling with the production of a pressed non-core blank in an open die is the most economical and does not require the use of reheating in the manufacture of rings made of medium-alloy steels. The technology of ring rolling of a profile blank obtained in a closed die does not require the use of additional heating after pressing, in the case of manufacturing rings with a simplified profile on the outer or inner diameters of the ring. In the manufacture of rings with a more complex profile on the outer and inner diameters of the ring, as well as rings made of high-alloy steels, the final decision on the need for additional heating is made depending on the temperature of the end of intensive plastic deformation for the selected steel grade of the ring. The technology of ring rolling with the production of a pressed profile blank in a die with reverse extrusion requires the use of reheating after the pressing operation before the ring rolling operation, and is recommended for the manufacture of rings from medium- and high-alloy steels with a complex profile section on the outer and inner diameters, wall thicknesses, with a ratio of wall thickness to outer diameter D within h / D = 0.011...0.016 and with a ratio of wall thickness to ring height L within h / L = 0.020...0.041. The proposed recommendations are intended for use in the development of technological support for the operation of the automated ring-rolling complex at OJSC “BELAZ”.