Fatigue-Greep Interaction Map for Tests with Dwell Time for ECD——The program of fatigue-creep interaction Ⅲ

This paper dealt with the effect of dwell time at max. stress on the fatigue-creep interaction behavior of superalloy ECD.
The results indicated that the cycle number of fracture decreased as the time of dwell at max. stress increased, However, the shape of interaction curve was not changed.The dwell at max stress intensified the creep effect resulting in the expansion of the interaction regions with predominant creep fracture (i, e.CC, CFC regions), and the FC mixed region moved to the area with high alternative stress, even the FCC region appeared instead of CFF region.
On the basis of macro-microanalysis of fracture the fatigue-creep interaction map for the tests with dwell time was constructed.It provided the basic information of fracture mechanisms and fracture cycles for the tests with hold time. However, the influence of hold time on the total rupture time was different:the total rupture time was increased for tests in F region, and for tests in C region it was decreased till a saturated value which is larger than that for the pure creep test at max. stress.