Relationship Between Creep Crack Growth Rates and Creep-Fatigue Crack Growth Rates in Austenitic Type-316 Steel.

摘要

The relationship between high temperature crack growth rates in Type 316 steel under creep conditions and combined creep-fatigue cycling is examined by consideration of the similarities between the underlying physical mechanisms of crack advance. In this way it is shown that creep crack growth rates may be used to estimate the limits to which creep-fatigue cycling can cause crack growth rates to accelerate in this steel. The usefulness of the derived limit is discussed with particular reference to practical stressing modes including load and displacement control. It is concluded that in Type 316 steel there is little difference between the behavior of a crack propagating under combined creep-fatigue cycling and a creep crack growing under some restraint. (ERA citation 05:036912)