Microstructure and mechanical properties of plasma arc additive interleaved structures

The plasma-arc additive bainitic steel-316L stainless steel dissimilar metal interleaved component has no defects, good forming and good comprehensive mechanical properties, which breaks through the “strong-tough” limitation of traditional materials. The relationship between microstructures and mechanical properties of interleaved components was studied through microstructure observation and mechanical properties testing. The results show that the microstructure of the structural parts in the bainitic steel area is strip bainite and residual austenite, the stainless steel area is mainly composed of austenite and ferrite, and there is a remelting zone with fine grain in the interwoven part. the microstructure of the bainite steel part in the remelting zone is granular bainite and thin-film residual austenite, and the microstructure of the stainless steel part is mainly equiaxed crystal. Tensile and impact experiments show that the increase of stainless steel content in structural parts leads to the reduction of tensile strength and the improvement of impact performance. When the content of stainless steel is relatively low, the tensile strength is higher than 1 200 MPa, the elongation after fracture is 9.5%, and the average impact absorbed energy is 159.25 J/cm², it has good strength and toughness, and the impact fracture is ductile fracture.