Profile cross rolling of high-interstitial austenitic stainless steels for application in plastics extrusion

FeCrMnCN stainless austenitic high‐interstitial steels (HIS) combine the properties of conventional FeCrNi austenites (superior ductility and surface corrosion resistance) with the potential of significant strengthening. This combination of properties makes them promising candidates for environments that require resistance to both wear and corrosion, e.g., processing of plastics. The aim herein is to make use of the high work‐hardening ability of HIS. Thus, machined preforms with an application‐related design are formed by profile cross rolling. The preform design enables a hardness increase in component regions that are most subjected to wear. Rolling of the specimens results in a very high surface quality with a roughness Rz in the range of 1 mm. Hardness measurements in rolled specimens confirm a significant hardness increase in the subsurface up to a depth of ≈2.5 mm. Hardness values of about 600 HV1 are yielded within a surface distance of ≈0.3 mm. Furthermore, tests on a modified pin‐on‐disc tribometer suggest that the wear behavior of the work‐hardened HIS is comparable with nitriding steel. Thus, the results of this study support the development of a forming technology for screws in corrosive environments.