Fatigue, creep and creep/fatigue crack growth behaviour of a nickel base superalloy at 700 deg C

摘要

This paper presents the results of a series of experimental tests on the high temperature behaviour of a Ni-base superalloy at 700 deg C; the material is used in the manufacture of aeroengine turbine discs. It is shown that the fatigue crack growth data correlates on the basis of the stress-intensity-factor range and creep crack growth rates appear to correlate on the basis of the C~* parameter. Constant load dwell periods introduce significant scatter in fatigue crack growth data. However, there is an indication that the threshold stress-intensity-factor range reduces when constant load dwell periods are introduced and that crack growth rates can be approximately correlated on the basis of stress-intensity-factor range.