Regular Article

Microstructure and mechanical properties relationship of additively manufactured 316L stainless steel by selective laser melting

¹ DEN – Service de Recherches en Métallurgie Physique, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
² DEN – Service d'Etudes Analytiques et de Réactivité des Surfaces, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
³ DEN – Service de Recherches Métallurgiques Appliquées, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
⁴ Cross-Cutting Skills Program on Materials and Processes, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette, France

^* e-mail: anne-helene.puichaud@cea.fr

Received: 24 January 2019
Received in final form: 24 September 2019
Accepted: 23 October 2019
Published online: 19 December 2019

Abstract

Additive manufacturing (AM) is rapidly expanding in many industrial applications because of the versatile possibilities of fast and complex fabrication of added value products. This manufacturing process would significantly reduce manufacturing time and development cost for nuclear components. However, the process leads to materials with complex microstructures, and their structural stability for nuclear application is still uncertain. This study focuses on 316L stainless steel fabricated by selective laser melting (SLM) in the context of nuclear application, and compares with a cold-rolled solution annealed 316L sample. The effect of heat treatment (HT) and hot isostatic pressing (HIP) on the microstructure and mechanical properties is discussed. It was found that after HT, the material microstructure remains mostly unchanged, while the HIP treatment removes the materials porosity, and partially re-crystallises the microstructure. Finally, the tensile tests showed excellent results, satisfying RCC-MR code requirements for all AM materials.