A case study on failure of backup roll hydrodynamic bearing in the Hot strip mill through CFD analysis.

This research paper investigates the failure of a Morgoil hydrodynamic bearing in the backup roll of a hot strip mill (HSM). The study focuses on the influence of mill parameters (load, speed, temperature) and radial clearance on the hydrodynamic film formation within the bearing, ultimately leading to its repeat failure. Using computational fluid dynamics (CFD) and MATLAB simulations, the effects of these parameters on oil film thickness, pressure distribution, and Sommerfeld number are analysed. The results are validated against established Raimondi and Boyd charts. Finally, recommendations for preventing future failures are provided, including establishing new discard criteria based on clearance, surface roughness, and oil properties.