High cycle rotating bending fatigue property in high strength casting steel with carbide free bainite

The present work shows a steel structure with bainitic ferrite dispersed on a matrix of carbon enriched retained austenite. The steel was produced using an air melting technique, and it was austempered at 200°C for 240 h. The steel presents tensile strength of ∼2 GPa. The authors report the new results of resistance to high cycle rotating fatigue in high strength bending life limit 10⁷ cycles. A fatigue strength of 593 MPa was obtained, a result that is higher than that presented by important engineering materials such as forged steel and austempered ductile iron, even with the presence of fracture type ‘fish eye’, which nucleates mainly on shrinkage defects.