The Rosette, Star, Tensile Fracture

Abstract
A type of tensile fracture topography encountered fairly often in certain temperature ranges with specimens from forgings, billets, rod, and bar of quenched and tempered steel, is the “star” or “rosette.” Having available several steels which had been shown to be capable of exhibiting the rosette, star, fracture, tensile testing was done to establish the temperature ranges for which this fracture configuration was applicable. Explanations of the fracture, and determinations of the fracture modes, were sought through experimentation involving metallography and the electron microscope, and by application of continuum mathematical plasticity-fracture theory.