The micromechanisms of fracture in an austenitic/ferritic super-duplex stainless steel (Zeron 100) have been studied for a range of product forms, including cross-rolled plate, conventional (ingot) route and powder route extruded pipe, hot isostatically pressed (HIP'd) powder, and weldments produced using both tungsten inert gas (TIG) and manual metal arc (MMA) techniques. The rolled plate material was also investigated after heat treatments at temperatures of 425 and 850°C, which were known to embrittle the material.