Simulation of Thermal Stress and Fatigue Life Prediction of High Speed Steel Work Roll during Hot Rolling Considering the Initial Residual Stress

Abstract

Considerable residual stress is produced during heat treatment. Compressive residual stress at the shell is conductive to improving the thermal fatigue life of a work roll, while tensile stress in the core could cause thermal breakage. In hot rolling, thermal stress occurs under the heating-cooling cycles over the roll surface due to the contact with the hot strip and water spray cooling. The combination of thermal stress and residual stress remarkably influences the life of a work roll. In this paper, finite element method (FEM) simulation of hot rolling is performed by treating the residual stress as the initial stress. Afterwards, the effects of the initial roll temperature and cooling conditions on thermal stress considering the initial residual stress are discussed. Lastly, the thermal fatigue life of a work roll is estimated based on the strain life model. The higher initial roll temperature causes a higher temperature but a lower compressive thermal stress at the roll surface. The surface temperature and compressive stress increase significantly in the insufficient cooling conditions, as well as the center tensile stress. The calculation of the fatigue life of a work roll based on the universal slopes model according to the 10% rule and 20% rule is reasonable compared with experimental results.

Model and Algorithm for Planning Hot-Rolled Batch Processing under Time-of-Use Electricity Pricing

“…In view of the fact that the numbers of roll-heated pieces in a rolling unit are small and the quality requirement is low, in this study, the principal pieces were focused on. The principal pieces processing met the following requirements [16,17].…”

Remote Cooling of Rolls in Hot Rolling; Applicability to Other Processes

“…Papers [7,8] study thermal stresses in bimetallic rolls. Advanced technology of production and heat treatment of these rolls allow to prepare favorable distribution of residual stresses.…”

“…Both papers present a general recommendation to keep the average roll temperature as low as possible. It should be noticed that in [8] fifty years old plant measurements of Events [1] were used as an input. Plant measurements of this kind are valuable and rare.…”

Application of Life-Dependent Material Parameters to Fatigue Life Prediction under Multiaxial and Non-Zero Mean Loading

“…Additional static loading could be an important factor affecting fatigue life [42,43]. A non-zero mean value of the stress is often caused by the effect of self-weight of the working element as well as the effect of initial tension in load-bearing elements (e.g., belts in gearboxes) or residual stresses [44][45][46][47]. The effectiveness of multiaxial fatigue models with life-dependent material parameters under cyclic multiaxial with zero mean stress has been validated in a few research papers [21,37,39].…”