The passivity of selective laser melted 316L stainless steel
Abstract
The passive film properties of as-received selective laser-melted 316L stainless steel (SLMed 316L SS) without obvious pores were studied and compared with those of wrought and solution-annealed (SA) SLMed 316L SSs. Among the samples, the as-received SLMed 316L SS had the lowest passive current density, which was attributed to two factors: the super high sub-grain boundary density increased the number of nucleation sites for passive film formation, and the micro-galvanic effect between the sub-grain boundary and the inner sub-grains also accelerated the rapid formation of a thick protective layer. The poor passivation and re-passivation abilities of the SA SLMed 316L SS were ascribed to the extensively precipitated nanosized oxide and sulfide particles, especially those at the grain boundary.
- Publication:
-
Applied Surface Science
- Pub Date:
- February 2020
- DOI:
- 10.1016/j.apsusc.2019.144495
- Bibcode:
- 2020ApSS..50444495K
- Keywords:
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- Selective laser melting;
- Stainless steel;
- Passive film;
- AFM;
- Cellular structure