The influence of water mist cooling on the durability of punches used in the die forging

The article examines studies on the effect of an additional cooling system on increasing the durability of punches used in the second operation of forging high‑nickel valves. To achieve this, the authors propose a mobile cooling system specifically designed for the second forging operation. To verify the results, operational tests were conducted under industrial conditions during the hot die forging of valves. The results were compared by measuring geometric changes in both the tools and forgings using 3D scanning, as well as analysing surface topography through scanning electron microscopy (SEM). Additionally, metallographic tests were performed on the punch cross-section. The results revealed a reduction in microstructural changes in the subsurface area responsible for hardness loss, which, over time, leads to plastic deformation of the surface. Consequently, the punch's durability in the analyzed process increased threefold. • Development of a method for cooling the punch in the water mist forging process. • 3D scanning and metallographic examination. • Presentation of own research and their validation base of industrial process. • Automated punch cooling system that increases its service life.