Cold Extrusion (Metal)
The proper steel selection for the application depends primarily on the work materials type, strength, thickness and workpiece geometry. The most critical failure mechanisms are adhesive wear, galling, cracking, abrasive wear and plastic deformation. In cold extrusion a punch applies a pressure to a slug of metal and causes it to flow in a controlled manner in the required direction.
Failure mechanisms in cold work tooling
Due to cyclic mechanical loading and sliding contact between work material and tool surface, the active surfaces of the tool are successively damaged. The destruction of the tool will sooner or later lead to quality problems on the formed parts (out of tolerance or bad surface qualities). The tool has then to be exchanged (total failure), reground or refurbished in some way.
This maintenance procedure means production standstill and accordingly loss of productivity. It is therefore very important that the tools can resist the different types of tool failure mechanisms in order to achieve high productivity and economical production. The selection of the right tool steel is thus directly linked to the resistance of the actual tool failure mechanism for the application.