Investigation on deformation behavior of high strength laminated heterostructured materials of ER120S-G high strength steel and 316L stainless steel fabricated by Wire-arc DED

Thin walls of 316L stainless steel (SS), ER120S-G high strength steel (HSS), and laminated heterostructured materials (LHM) were successfully fabricated using the wire arc directed energy deposition (Wire-arc DED) technology, and their microstructure, chemical composition, and mechanical properties were comprehensively studied. Additionally, the deformation behavior of different layers and layer interfaces in the LHM thin walls was studied through interrupted tensile tests. The chemical composition of the different layers in the LHM thin walls changed due to element dilution, which led to alterations in the microstructure. Deformation behavior varies across different regions and phases of the LHM sample. Before necking in the LHM sample, the geometrically necessary dislocations (GNDs) accumulation rate in the FCC phase of the 316L SS layer was the fastest, followed by the BCC phase of the ER120S-G HSS layer, and finally the BCC phase of the 316L SS layer. After necking, the GNDs accumulation rate in the BCC phase of the ER120S-G HSS layer became the fastest, followed by the FCC phase of the 316L SS layer, and lastly the BCC phase of the 316L SS layer. This non-uniform deformation mechanism differs significantly from the deformation mechanisms of traditional homogeneous materials. During the loading deformation of the LHM, stress-induced martensite generated in 316L SS layer. The grains of ER120SG layer were deformed along the tensile direction and developed strong {110}<100> Goss texture, {110}<110> R-Goss texture, and {001}<110> R-Cube texture. This study provides guidance for the development and engineering application of laminated heterostructured materials.