Experimental Evaluation of Fatigue Resistance of ETG 88 and C45+C Steels Considering Stress Concentrators and Scale Factor

摘要

The paper contains results of an experimental evaluation of fatigue properties of two steel types used for shaft manufacture, namely rather conventional, medium carbon high quality C45+C steel and quite modern low alloy ETG~R 88 steel, recently developed with the aim to reduce overall manufacture cycle costs together with maintenance of high mechanical and fatigue properties. Actual critical fatigue damage modes of shafts, namely at stress concentrators of shaft shoulders, was experimentally modeled by small and quite large notched specimens loaded by rotating bending. ETG~R 88 steel was characteristic by somewhat higher fatigue resistance, but higher scatter of results. Differences are discussed considering chemical composition, microstructure and results of simple analyses of fatigue fracture surfaces.