Ductile fracture of duplex stainless steel with casting defects

Experimental and numerical studies were carried out on CF8M steel with spec ial regard to the influence of casting defects i.e. shrinkage cavities on f racture behaviour. As-received and thermally aged materials were studied. P hysical steps of damage in specimens containing casting defects were observ ed using in-situ tensile tests in a scanning electron microscope. Mechanica l properties of duplex stainless steel were characterised using three-point bend tests of three types of specimens - defect free, pre-cracked, and con taining shrinkage cavities. These mechanical tests were simulated using Gur son's model including crack nucleation. A modelling of the shrinkage caviti es is proposed in order to study their influence on the mechanical response of the specimen. (C) 2001 Elsevier Science Ltd. All rights reserved.