Creep deformation and failure properties of 316 L stainless steel manufactured by laser powder bed fusion under multiaxial loading conditions
File(s)
Accepted version
Author(s)
Williams, Richard J
Al-Lami, Jalal
Hooper, Paul A
Pham, Minh-Son
Davies, Catrin M
Type
Journal Article
Abstract
316 L stainless steel has long been used in high temperature applications. As a well-established laser powder bed fusion (LPBF) alloy, there are opportunities to utilise additive manufacturing in such applications. However, the creep behaviour of LPBF 316 L under multiaxial stress conditions must first be quantified before such opportunities are realised. Uniaxial and double notched bar creep tests have been performed and characterised using power-law relations to evaluate the creep strain and rupture properties of LPBF 316 L. The creep response was found to be anisotropic with specimen build orientation, with samples loaded perpendicular to the build direction (Horizontal) exhibiting 8 times faster minimum creep rates than samples built parallel to the build direction (Vertical) and significantly shorter rupture lives. This was mainly attributed to the columnar grain structure, which was aligned with the build direction of the LPBF samples. The multiaxial creep rupture controlling stress was determined and found to be a combination of the equivalent and max. principal stress. X-Ray CT measurements in selected samples illustrated that the samples were approximately 99.6% dense post-build and the quantity of damage post testing was determined. Optical and EBSD microstructural characterisation revealed intergranular creep damage present in the specimens, however rupture was ultimately trans-granular in nature and influenced by the presence and orientation of pre-existing processing defects relative to the sample build and loading direction.
Date Issued
2021-01
Date Acceptance
2020-11-09
Citation
Additive Manufacturing, 2021, 37, pp.1-11
ISSN
2214-8604
Publisher
Elsevier BV
Start Page
1
End Page
11
Journal / Book Title
Additive Manufacturing
Volume
37
Copyright Statement
© 2020 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
AWE Plc
Identifier
https://www.sciencedirect.com/science/article/pii/S2214860420310782?via%3Dihub
Grant Number
See further info
Subjects
0910 Manufacturing Engineering
Publication Status
Published
Article Number
101706
Date Publish Online
2020-11-11