Dramatic improvement of impact toughness for the fabricating of low-carbon steel components via submerged arc additive manufacturing

Abstract Submerged arc additive manufacturing (SAAM) with high deposition efficiencies and unique cyclic re-heating was firstly introduced to fabricate the low-carbon steel product in this work. The microstructure and mechanical properties of the SAAM product was studied. The results showed that the intermediate zone of the as-deposited component was mainly composed of equiaxed α-Fe grains and possessing obvious homogeneous characteristics along the building direction. The impact energy of the component was vastly improved to over 300 J at −60 °C with little loss of strength. The tensile yielding strength ~346 MPa, elongation ~39% in vertical direction were competitive to that in horizontal direction, showing a fancy isotropic characteristic. The exclusive intrinsic heat treatment of SAAM holds the decisive role for this dramatic phenomenon.