Innovative warm rolling plus electromagnetic shock treatment for high-quality M50 bearing ring manufacturing

M50 bearing steel is a high-carbon alloy extensively utilized in the aerospace industry due to its exceptional mechanical properties at elevated temperatures. Its production typically involves cold ring rolling (CRR) at room temperature and hot ring rolling (HRR) at high temperatures. The CRR process offers high precision but is susceptible to microcrack formation, while HRR can effectively eliminate defects but may induce coarse grain structures, reducing material performance. To address these issues, this study proposes a novel warm ring rolling (WRR) process, which integrates the benefits of both CRR and HRR. The aim is to optimize the forming rate while improving the plasticity limit and microstructural integrity of the material. Additionally, the study investigates the hot deformation behavior of M50 bearing steel under various deformation conditions and derives strain-compensated constitutive equations to predict its deformation, failure, and fatigue characteristics during the warm forming process. Temperature-dependent compression tests, along with electromagnetic shock treatment (EST) experiments, were also conducted. Results indicate that increasing the compression temperature reduces void formation, while EST significantly mitigates voids and promotes the dissolution and fragmentation of carbides. Furthermore, under the influence of EST, the average grain size of the WRR specimen notably decreases. The study concludes that the optimal processing temperature for EST–WRR technology is 400 ℃, with a current density of 140 A/mm². This research provides a theoretical foundation for the future processing and performance optimization of M50 bearing steel and validates the efficacy of EST in the WRR process.