Microstructure, mechanical properties, and corrosion behaviour of wire arc additive manufactured martensitic stainless steel 410 for pressure vessel applications

Abstract

High-strength martensitic stainless steel 410 (MSS 410) was successfully fabricated without defects via wire arc additive manufacturing (WAAM). The microstructural features, mechanical properties, and corrosion performance of WAAM-processed MSS 410 were examined. Microstructural analysis revealed the existence of equiaxed and coarse columnar dendrites and the formation of residual delta-ferrite and retained-austenite (RA) was confirmed within the martensitic matrix. The fraction of residual ferrite and RA varied along the building direction due to complex thermal cycles. Uni-axial tensile results exhibited anisotropic behavior and are related to layered microstructure. Microhardness values varied from bottom to top (384–460 HV). Ductile mode of failure was noticed, and the existence of RA influences the ductility. The corrosion behaviour of the WAAM 410 specimens in 3.5% NaCl solution was considerably acceptable, and the corrosion rate ranged between 0.05 and 1.37 mpy. This shall be attributed to the absence of defects, microstructural features, and ferrite fraction in the WAAM 410 samples. The mechanical properties and corrosion behaviour of the WAAM 410 were comparable to the wrought grade and are suitable for pressure vessel applications with adequate corrosion resistance.