Machinability of austenitic stainless steels 304/304L for medical applications

Abstract: Austenitic stainless steels 304 and 304L are widely used for their excellent properties, including corrosion resistance and toughness. However, their machinability is challenging due to high work hardening and low heat conductivity. This study examines the effect of alloy composition, microstructure, and surface integrity on the machinability of 304 and 304L during turning processes. Variations in alloy composition showed minimal effect on machinability, whereas micro-hardness and subsurface residual stress significantly influenced cutting forces, surface roughness, and tool wear. Specifically, machinability worsened with hardness exceeding 350 HV and compressive residual stress below -130 MPa.