MICROSTRUCTURAL AND THERMAL STABILITY OF SELECTIVE LASER MELTED 316L STAINLESS STEEL SINGLE TRACKS

• Pavel Krakhmalev Department of Engineering and Physics Karlstad University, Sweden
• Ina Yadroitsava Central University of Technology, Free State, South Africa
• Gunnel Fredriksson Department of Engineering and Physics Karlstad University, Sweden
• Igor Yadroitsev Central University of Technology, Free State, South Africa

DOI:

https://doi.org/10.7166/28-1-1466

Keywords:

stainless steel, selective laser melting, microstructure, heat treatment

Abstract

To remove residual stresses, an as-built SLM object is usually post- treated. This treatment can affect the microstructure, changing the final mechanical characteristics. This investigation is focused on the microstructural characterisation of 316L austenitic stainless steel in as-built and annealed conditions. The SLM microstructure was relatively stable up to 900°C, when cell boundaries start to disappear. At higher temperatures, an insignificant grain coarsening was detected. These microstructural changes caused a gradual drop in the hardness. The obtained result is background for the future development of post-treatment regimens to achieve a high level in the final mechanical properties of SLM objects.