Application of Data on Creep Behaviour In Life-Time Assessment

摘要

In material exposed to high temperaure and mechanical stress, there exist many damage mechanisms in its volume and on surface. One of these is the creep process which can be characterised with a number of quantities, such as time to fracture, creep rate, limit strain at rupture and others. Among these, mainly the time dependence of strain is of major significance as, besides the time to fracture, the factors limiting the component service life can include creep deformation as well. Moreover, when assessing the expected life of structures, stress redistribution during the creep process must be taken into account, as the service life assessment based solely on elastic analysis is likely to result in many applications in too conservative service life estimates. While various constitution equations of the creep process have been published, none of these can be considered to present the full solution to the problem, as the parameters in these equations are still dependent on temperature and stress.