Stress intensity factor evaluation for fatigue crack in working roll due to hot rolling process

Crack growth is one of the main causes of failure of hot rolling rollers, which also causes damage to other parts. For this reason, three-dimensional modeling of surface crack, the study of the effect of different factors and different phenomena on roller fatigue life and the effect of stress distribution are important research topics. To increase the efficiency of rollers and propose practical methods, in this study, the stress intensity factors of surface cracks in rollers fabricated from High Chromium Steel (HCS) in the hot rolling process are modeled in three dimensions. Each component modeled separately, the complexity of problem solving is reduced and the speed of solution is improved using the proposed method. In this regard, first, the types of cracks and their causes in the roller as well as the effect of residual stresses on the roller are analyzed. By selecting HCS roller and sheet, modeling and stress analysis are performed by finite element method. In addition, the boundary element method was used to simulate the three-dimensional cracks and the stress intensity factors. The results show that the values of stress intensity factors at the deepest point of the crack front are maximum.

Keywords:

Stress intensity factor , Crack , Working rolls , Boundary element method , Hot rolling process