Review of selected methods of increasing the life of forging tools in hot die forging processes

The work concerns the possibilities of applying various methods with the purpose to increase the life of forging tools, which, based on the experience and research of the author, realized in cooperation with the forging industry, exhibit the highest effectiveness in improving the life of forging tools. Durability of forging device is determined by the presence of destructive mechanisms under the extreme work conditions of forging tools - a high cyclic mechanical loads (up to 1000 MPa) and thermal (from 800 °C to 800 °C on the surface). The tool life is also an element which affects the quality of the forgings, as too high and intensive wear/damage of the dies and stamps causes a change in the geometry of the manufactured product, and any surface faults (cracks, defects) are represented on the forged product. The presented investigation results refer to: selection of the tool material for a particular process, its adequate thermal and thermo-chemical treatment, use of surface engineering techniques: hybrid with the use of coatings applied physically from the gaseous phase, use preventive pad welding, as well as optimization of the die shape and construction of the instrumentation set. The work also presents the use of control and measurement systems, allowing for full monitoring of the forging process, and the application of innovative solutions (use of acoustic emission signal) allowing for an effective improvement of the life of the forging tools and instrumentation. At present, by way of applying a range of methods, which the most popular shows in this article, as well as many other computer-aided tools, it is possible to solve many problems related to a short tool life.