Microstructural and intergranular corrosion properties of Inconel 625 superalloys fabricated using wire arc additive manufacturing

Abstract

Inconel 625 superalloy samples were fabricated using wire arc additive manufacturing (WAAM). The phase composition, microstructure, anti-corrosion, and mechanical properties of the Inconel 625 WAAM samples were analyzed. The microstructure of the Inconel 625 WAAM alloy showed good forming quality, no defects, and good metallurgical bonding within the specimens. The metallographic structure exhibited primarily γ -Ni and granular precipitated phases; the average microhardness of the transverse and longitudinal cross-sections of the sample was 243.5 and 243.3 HV _0.1 , respectively. Yield and tensile strength as well as elongation, decrease in area, and the room-temperature impact values of this alloy were equal to 450 and 736 MPa, 38% and 52%, and 152 J, respectively. The intergranular corrosion test results indicated that the average corrosion rate of the sample is 0.609 mm/year, indicating excellent resistance to intergranular corrosion.

Keywords

• Inconel 625
• wire arc additive manufacturing
• microstructure
• intergranular corrosion