The material behaviors of two types of bearing steels at hot working conditions are investigated. Stress-strain curves at various temperatures (900–1300°C) and strain rates (1–50/s) are obtained by compression tests with a computer controlled servo-hydraulic Gleeble 3800 testing machine. Elongation and reduction of the area are also obtained by tensile tests with the Gleeble 1500 testing machine. Flow stresses are calculated from the experiments and are used to predict the temperature distribution and the metal flow of a workpiece during a multistage hot forging process of a bearing race. A rigid-thermoviscoplastic finite element method is applied. The experimental and numerical results are summarized to reveal the reasons for internal crack formation.

Issue Section:
Technical Papers
Keywords:
forging, hot working, stress-strain relations, temperature distribution, finite element analysis, viscoplasticity, cracks, machine bearings, steel, hot forging process, bearing steel, stress-strain curve, hot compression test, hot tensile test, computer controlled servo hydraulic testing machine, rigid-thermoviscoplastic finite element method
Topics:
Bearings, Compression, Forging, Fracture (Materials), Machinery, Steel, Temperature, Flow (Dynamics), Selective catalytic reduction, Steel catenary risers, Stress-strain curves, Stress, Deformation, Finite element methods, Temperature distribution, Testing
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