Metal Additive Manufacturing Conference 2018

The SLM (Selective Laser Melting) is an additive manufacturing technique (AM) that is based on a layer by layer laser melting of metal powders deposited on a moving stage in order to obtain a controlled geometry of the component (3D printing). Many metals can be processed by using this technique such as Ti, Al or Ni alloys, tool or stainless steels. The aim of this work is to determine the corrosion properties of an AISI 316L stainless steel produced by 3D printing and to compare these properties to the ones of a wrought AISI 316L stainless steel. The samples were produced by SLM (Concept laser) using a chessboard laser scan. The as produced material, as well the wrought material, underwent a post production heat treatment at different temperatures in order to observe the material microstructural evolution. The microstructures were investigated by SEM and light microscopes as well as by SKPFM in order to determine the presence and evolution of the different formed phases as a function of heat treatments. Potentiodynamic polarization curves in 3,5 wt% NaCl were obtained at 3 different temperatures (RT, 40°C and 60°C) on polished samples. In addition, micro-cell electrochemical test were performed at room temperature. After polarization tests samples were characterized in order to determine the preferential corrosion sites. These preliminary analyses have shown that the AM material presents a dual phase microstructure as well as the presence of small defects (porosities) affecting the corrosion behaviour.