On time-dependent crack growth parameters in plasticity and creep fields

Abstract

Rate and non-rate parameters are examined for correlation of time-dependent crack growth rates under static control conditions. Experimental data on single edge notch specimens of IN718 at 593degreesC, compact tension specimens of stainless steel 304 at 538degreesC and X20CrMoV 12 1 steel at 545degreesC are used to examine the performance of rate parameters C-pc, (J) over cap, (J) over dot * and non-rate versions of these parameters which are computed either from approximate equations or finite element analyses. It is found that rate parameters can correlate time-dependent crack growth rates whether the crack tip field is dominated by plasticity or by creep. Non-rate parameters are found inadequate in either circumstance.