Correlation of Data from Standard and Precracked Charpy Specimens with Fracture Toughness Data for HY-130, A517-F, and HY-80 Steel

Fracture toughness data were obtained for three constructional alloy steels having yield strengths of 958, 752, and 552 MPa (139, 109, and 80 ksi) (HY-130, A517(F) [Unified Numbering System UNS K11576], and HY-80, respectively) by testing conventional Charpy V-notch (CVN), fatigue-precracked Charpy, and plane-strain fracture toughness KIc specimens. The data were used to evaluate proposed correlations between KIc data and data obtained with Charpy-type specimens and to develop additional correlations. Of the five correlations examined, a method based on standard CVN results that incorporated a temperature shift to relate impact to static data gave slightly better estimates of KIc values in the transition temperature region than the others. However, the best results over the widest temperature range were obtained from a correlation method based on a J integral estimation that predicts KIc values from the results of slow-bend tests of fatigue-precracked Charpy-type specimens.