Analysis of wear behavior of powder metallurgy tools in shear cutting of electrical steels

The shear-cutting process of electrical steels for electrical engines' rotors and stators influences the properties of the shear-cut edges. The properties such as geometry and mechanical and electromagnetic properties of shear-cut edges depend on the wear behavior of the tools. This study examines tool wear in three powder (PM1, PM8, PM10) metallurgical tool steels during shear cutting of electrical steel. PM1 is intended for high-performance applications owing to its unique mixture of boride and carbide precipitates. PM8 is a high alloyed Cr-Mo-V tool steel tailored for abrasive wear applications with a certain amount of ductility, and PM10 is a nitrogen alloyed tool steel specifically designed for applications where adhesive wear resistance is required. Tool wear and shear-cut edge properties were analyzed at four different intervals of punch strokes for 8% and 16% cutting clearances. The experimental study found that the 8% clearance caused excessive chipping in punch corners for all three materials, mainly PM10, which chipped in all corners at the end of 108,000 strokes. In contrast, PM1 demonstrated better chipping resistance, particularly at 16% clearances. Furthermore, PM1 showed superior resistance to edge wear for various punch strokes and clearances.