High Speed Milling of Hardened Steel Convex Surface

This paper presents a contribution to hardened tool steel milling studies. High speed milling is largely utilized to substitute some EDM and polishing operations, mainly in hardened tool steel finishing. Tool path strategy may either enable good surface finish or contributes to generate high roughness values and poor surface finish. Tool inclination (angle between tool axis and workpiece surface) influences the system response to vibration. In this work, several milling experiments were performed in a circular convex AISI D6 hardened steel workpiece, having as input variables feed direction (upward and downward the circle) and tilt angle (tool inclination). The main results indicate that upward tool path presented mostly high roughness values which were also influenced by tool inclination. Downward tool path presented low roughness values and was less influenced by tool inclination. Upward tool path and positive tool inclination should be avoided because they presented roughness values incompatible to EDM process substitution.