Closed-Die Forging of Rectangular Billets with Diamond-Shaped Dies

Summary The forging of billets in diamond-shaped closed dies has been investigated. Experiments were conducted at room temperature using Plasticine to simulate the forging of hot-steel. Billets of rectangular cross-section of various height/width ratios were forged between diamond-shaped closed dies of different angles. The effects of die and workpiece geometries and lubrication on die-filling capacity and deformation characteristics, were examined. To observe the metal flow during the process, grid lines were printed on one of the end faces of the billet and flow patterns were determined from a series of photographs of the deformed lines taken at increments of die-stroke. From these deformed patterns deformation modes were able to be suggested. A theoretical study of the metal flow in the initial stages of forging was also conducted. Slip-line field solutions are given to predict the incipient modes of deformation and these are compared with the observed flow patterns.