Enhancing Mechanical Properties: Exploring the Effect of Annealing Temperature on Wire Arc Additively Manufactured High-Strength Steel

This study investigates the mechanical properties of exceptionally high-strength steel produced by wire and arc additive manufacturing (WAAM), using the 304 stainless steel wire and the low carbon wire (LCS). The study found that annealing treatment can enhance the steel's mechanical properties. The microstructure in the LCS layer changed from ferrite to bainite and then to a mixture of austenite, pearlite, and bainite with increasing annealing temperature. In contrast, the SS layer retained its martensitic structure, albeit with altered lath sizes. The annealing treatment also improved the orientation of the grains in the steel. The optimal annealing temperature observed for the steel was 900 celcius, which resulted in a maximum tensile strength of 1176 MPa along the Y direction and 1255 MPa along the Z direction. Despite the superior mechanical properties, the LCS layer still exhibited failure during tensile testing due to its lower hardness. The study suggests that annealing treatment can be a useful technique for enhancing the mechanical properties of high-strength steel in WAAM applications.