Experimental study on fatigue crack growth of QSTE420TM steel with a single dwell-overload and a combined prediction model

摘要

To study the fatigue crack behaviors of QSTE420TM steel under constant amplitude with a single dwell-overload, a series of experiments are performed. The dwell time changed from 0 s to 10(6) s. The result shows that the dwell overload retardation is more distinct than the single overload. The retardation degree is not proportional with the dwell time, its greatest level appears when the dwell time lasted 10(4)s, then it gradually becomes stable. A combined model, which considers the effects of both residual stress and crack closure, is proposed by introducing a dwell factor to describe the plastic zone at the crack tip. (C) 2021 Elsevier Ltd. All rights reserved.