Fabrication and characterization of laminated heterostructured material with ER120 S-G and SS316L using wire and arc additive manufacturing

A Laminated Heterostructured Material (LHM) thin wall with SS316L and ER120S-G was fabricated using wire and arc additive manufacturing. The study primarily investigates correlation between microstructure and mechanical properties in LHM sample. The ER120S-G region of the resulting LHM displays a structure of feather-like bainite and lath martensite while the microstructure of the SS316L region is residual austenite and lath martensite. LHM achieved the Columnar to Equiaxed Transition (CET) during transition from SS316L deposits to ER120 S-G deposits, benefiting from the changes in solute concentration, temperature gradient and solidification rate between heterogeneous materials. The LHM specimen shows outstanding mechanical properties, with a transverse tensile strength of 1223.274 MPa and corresponding elongation of over 19%. Compared with as-fabricated ER120S-G, the tensile strength of LHM has been significantly improved, which is unique compared to previous studies. This is due to the reduced heat input between LHM and as-fabricated ER120S-G, resulting in grain refinement and martensite transformation in SS316L layer caused by interlayer remelting.