Ring rolling work rolls life estimation by means of Manson-Halford-Haibach method

Ring rolling process is used in the production of seamless rings.The most important advantages of these rings are favorable grain flow and crack growth resistance. Aircraft engine spools are usually produced by means of this process. Failure of the work rolls during forming of spools leads to unacceptable geometrical structural and irreparable damages. Evaluation of the work rolls life of the ring rolling machine has a direct effect on the properties of the output ring. Initially, different types of life estimation and cumulative damage assessment methods were studied. By making use of Abaqus simulation, the loading history was extracted and applied to the work rolls. According to the loading history, stress-life method and cumulative damage relations were performed. The results of the research shows that the main roll is significantly affected by mechanical stresses. On the other hand, the mandrel is affected by thermal stresses by applying the thermo-mechanical forces. In general, in order to extend the work roll’s life, of the work rolls and reduce the effects of the thermo-mechanical stresses, the uniformity of temperature during work rolls operation should be maintained. So that proper cooling will have a significant effect on the service life. In addition, the effect of bending stress on the mandrel life is not significant.