Investigation of the key process parameters in the hot forming of a shackle

To investigate the impact of the variations of different input parameters in the multi-stage hot forging process of a shackle, an analysis is carried out through numerical simulations of the whole manufacturing process. Due to the complexity of the process and the large number of factors influencing the thermo-mechanical forming process, the investigation is focused on the workpiece positioning, the temperature of the tools, the transportation time and the contact-friction conditions. The analysis is narrowed down to the key stages of the process that are closed-die forging and ram bending. Coupled with experimental measurements, a comparison of forging loads, functional dimensions and shackle geometry is presented. It is shown that the conformation of shackle geometry to the industrial specifications depends mainly on the workpiece positioning and the transportation time. The dispersion measured in the forging load and in the main dimensions can thus be explained and these observations can be used to improve the manufacturing process for shackles.