Research on radial-axial near-net rolling feed process of large 42CrMo ring

The plastic deformation process of large 42CrMo steel rings is inherently complex, and improper rolling parameters often lead to instability, eccentricity, and geometric defects. In this study, a finite element model of radial-axial ring rolling for large 42CrMo steel rings with outer diameters of Φ2640 mm and Φ2950 mm was developed to systematically investigate the effects of various mandrel feeding strategies on dimensional accuracy, ovality, temperature distribution, and equivalent plastic strain distribution. The results indicate that the constant outer diameter growth rate strategy reduced the ring ovality to 6.84 and 8.3, which is superior to the 10.35 and 11.74 observed under the constant per-rotation feed approach. Additionally, this method achieved a relative diameter error reduction to approximately 0.9%, indicating enhanced dimensional control. In contrast, the constant per-rotation feed strategy exhibited superior performance in terms of temperature standard deviation (40.4, 39.9) and equivalent strain standard deviation (2.9, 3.74), compared to the constant outer diameter growth rate approach (43.1, 42.3; 3.13, 4.14), demonstrating improved thermal control and deformation uniformity. Overall, the optimized rolling strategy proposed in this study provides theoretical guidance and practical reference for improving the forming quality and dimensional precision of large 42CrMo steel rings.