Modeling of Carbide Spheroidization Mechanism of 52100 Bearing Steel Under Warm Forming Conditions

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Physical metallurgy and materials science, 2019-02, Vol.50 (2), p.936-946
• Main Authors: He, Tao, Huo, Yuanming, Shi, Xiaojun, Chen, Shoushuang
• Format: Article
• Language: English
• Subjects: Bearing steels; Carbides; Characterization and Evaluation of Materials; Chemistry and Materials Science; Constitutive equations; Constitutive relationships; Deformation mechanisms; Dislocation density; Genetic algorithms; Materials Science; Mathematical models; Metal industry; Metallic Materials; Nanotechnology; Optimization techniques; Phase transitions; Spheroidizing; State variable; Structural Materials; Surfaces and Interfaces; Thin Films
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-018-5050-0

Direct deformation spheroidization of bearing steel can produce a fine and homogeneous microstructure. Warm-compression experiments were performed to investigate the carbide spheroidization behavior of 52100 bearing steel at temperatures of 650 °C to 750 °C and strain rates of 0.1 to 10.0 s −1 . A set of mechanism-based unified constitutive equations was developed using the internal state variable method to describe the carbide spheroidization and metal flow behaviors of 52100 steel under warm deformation. The carbide spheroidization fraction, dislocation density, and phase transformation were modeled and correlated with unified constitutive equations. Material parameters in the constitutive equations were determined using genetic algorithm optimization techniques. The developed constitutive equations were validated by comparing the predicted and experimental results. Good consistency between these results indicated that the carbide spheroidization and metal flow behavior could be predicted using these constitutive equations.