Fracture Appearance of Steels in Transition: Experimental Observations and Measurements

Measuring the shear fracture appearance (SFA) of steel in the ductile-to-brittle transition region is challenging, largely because many modern steels have complicated mixtures of brittle and ductile fracture features that the carbon steels used to develop SFA measurements did not possess. Features of Charpy impact specimen fracture surfaces for nine different steels are reported here. The mixtures of ductile and brittle fracture surface features observed in the transition regions of these steels are presented in context with their instrumented impact data and fractographs illustrating the SFA measurements. The study then discusses the accuracy of the SFA measurements and suggests ways to improve them. These data can be used for future work focused on improving SFA measurements and will be of use to engineers interested in the ductile-to-brittle transition in steel and the fracture surface features related to it.