Hot crimping in a special profile matrix of axisymmetric hollow workpieces from high carbon steel

Abstract

Using the finite element method, mathematical models were created and studies were carried out of direct and reverse methods of hot crimping in a matrix of a special profile of hollow workpieces made of high-carbon steel with a variable wall thickness along the height. A plastic model of metal and cylindrical coordinates are used. By calculation, the shape and dimensions of the initial workpiece for crimping were established, which provided the required dimensions of the product. Before crimping, a part of the billet was heated along the height, which was subject to deformation in the matrix. The use of a matrix of a special profile with a deforming surface made with annular protrusions made it possible to obtain a product in one step due to a decrease in the influence of friction forces during shaping. The deformation rate is determined to comply with the hot deformation mode during the crimping. The dependences of the axial force on the deforming tool on the movement of punches and the distribution of specific forces on the contact surfaces are established. The use of direct crimping leads to a decrease in forces modes and specific forces on the tool. The final stress-strain state of the metal, the shape and dimensions of the product are determined. According to the distribution of strain intensity, an assessment was made of the elaboration of the metal structure by plastic deformation. Based on the simulation data, a design of the general view of the die tooling for direct crimping has been developed.