EXAMINATION OF DEGRADATION FREQUENTLY REPAIRED SHEARING AND FORMING TOOLS

The article describes the renovation of repeatedly worn shearing tools working cold up to 200 °C. The material from which the cutting punch is made of carries the trade name CALDIE. It is delivered from the smelter in the condition after soft annealing and subsequently it is refined. A worn or damaged edge is chamfered and welded afterwards by technology of micro-TIG in pulse mode. To restore the geometry of the damaged edge is used an intermediate layer between the base material and the final hard layer the ferritic-austenitic wire Cronitex RC 220. Eventually, the final hard layer is welded to the intermediate layer, either Cronitex RC 60 or RC 63. After welding, the tool is machined to the required dimensions and then integrated back into production. The main goal was to evaluate the possibility of extending the life of cutting tools and reducing the implementation of already inefficient repairs. For assessment several destructive tests were performed - macrostructure, microstructure, microhardness measurement and EDS analysis.