Triple structuration and enhanced corrosion performance of 316L in laser powder bed fusion.

This work focuses on the influence of the feedstock powders on the microstructural properties and corrosion behavior of 316 L stainless steel (SS) produced by laser powder bed fusion (L-PBF) from two different suppliers. Microstructural investigations conducted after additive manufacturing reveal many particularities depending on the powders. These microstructural differences lead to a different corrosion behavior in boiling nitric acid containing oxidizing ions. The presence of the triple structuration (grains, large cells, small internal cells) shows a positive effect on intergranular and cellular corrosion resistance. In both cases, L-PBF 316 L SS provides better resistance to intergranular corrosion than wrought 316L SS. • Impact of raw material properties on the microstructure of 316L SS produced by laser powder bed fusion. • A new triple structuration (grains, large cells and small internal cells) has been evinced. • Printed samples exhibited better corrosion resistance compared to wrought 316L SS in strongly oxidizing acidic medium. • The new microstructure shows a slightly intergranular attack and improves cell corrosion resistance. [ABSTRACT FROM AUTHOR]