Effect of heat treatment on microstructures and mechanical properties of SS316L by micro selective laser melting

Jin Fu, Shuo Qu, Junhao Ding, Xu Song, Mingwang Fu

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

Abstract

Recently, micro selective laser melting (μSLM) system equipped with finer laser beam has been developed to improve additive manufacturing resolution. The microstructures and properties of μSLM produced metals and alloys could be different from those by conventional-size SLM, which warrants further investigation. Moreover, the widely used material, SS316L stainless steel, demonstrates unique cellular structures and excellent combination of strength and ductility after SLM. How the microstructures evolve after heat treatment and affect the mechanical properties remain to be clarified for μSLMed SS316L. In this study, the effect of heat treatment on the microstructures and mechanical properties of μSLMed SS316L was studied. Two heat treatment methods, namely HT650°C-2h and HT950°C-2h, were employed. It is found that the heat treatment has no effect on phase formation, and a preferred grain growth orientation with (110) plane along building direction and a single austenite phase was detected in all samples. Cellular structures were observed in as-printed samples and found to grow up a little bit after HT650°C-2h, but disappear after HT950°C-2h. Besides, more carbides are detected after HT650°C-2h, while they are partially dissolved after HT950°C-2h. For mechanical properties, the as-printed sample shows the best combination of strength and ductility, thanks to the strengthening effects from cellular structures and dislocations. The inferior mechanical properties after heat treatment is attributed to reduction of dislocations and disappearance of cellular structures. In addition, the presence of carbides can significantly reduce the ductility.

Original languageEnglish
Title of host publicationAdditive Manufacturing; Advanced Materials Manufacturing; Biomanufacturing; Life Cycle Engineering; Manufacturing Equipment and Automation
PublisherAmerican Society of Mechanical Engineers
ISBN (Electronic)9780791885062
DOIs
Publication statusPublished - Aug 2021
EventASME 2021 16th International Manufacturing Science and Engineering Conference, MSEC 2021 - Virtual, Online
Duration: 21 Jun 202125 Jun 2021

Publication series

NameProceedings of the ASME 2021 16th International Manufacturing Science and Engineering Conference, MSEC 2021
Volume1

Conference

ConferenceASME 2021 16th International Manufacturing Science and Engineering Conference, MSEC 2021
CityVirtual, Online
Period21/06/2125/06/21

Keywords

  • Heat treatment
  • Mechanical properties
  • Micro selective laser melting
  • Microstructures
  • Stainless steel

ASJC Scopus subject areas

  • Industrial and Manufacturing Engineering

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