Mechanical properties of Inconel 718 welds performed by gas tungsten arc welding

• Published in: International journal of advanced manufacturing technology Vol. 94; no. 9-12; pp. 3949 - 3961
• Main Authors: Cortés, R., Barragán, E. R., López, V. H., Ambriz, R. R., Jaramillo, D.
• Format: Journal Article
• Language: English
• Published: London Springer London 01.02.2018; Springer Nature B.V
• Subjects: CAE) and Design; Charpy impact test; Computer-Aided Engineering (CAD; Engineering; Filler metals; Gas tungsten arc welding; Hardening; Heat affected zone; Heat recovery; Heat treating; Impact strength; Impact tests; Industrial and Production Engineering; Mechanical Engineering; Mechanical properties; Media Management; Metals; Microhardness; Nickel base alloys; Original Article; Post-weld heat treatment; Superalloys; Welded joints; Yield strength; Yield stress; Mechanical properties; GTAW; Post weld heat treatment; Inconel 718
• ISSN: 0268-3768; 1433-3015
• DOI: 10.1007/s00170-017-1128-x

Gas tungsten arc welding (GTAW) was used to join plates of Inconel 718. The mechanical properties were determined by tensile, microhardness, and instrumented Charpy impact tests. An ERNiFeCr-2 filler metal fed by a semi-automatic mechanism was used. Partial dissolution of the strengthening phases, γ′ and γ″, induced a soft region (~ 225 HV 1.0 ) in the heat-affected zone (HAZ) during welding. The yield strength (371.3 MPa) of the as-welded joint is approximately 45% of the base material in aged condition (822.7 MPa). The welds were subjected to a hardening recovery post weld heat treatment (HRPWHT). Impact testing of the hardened welds revealed a reduction of 17% in energy absorbed with respect the aged base material. Hardness measurements showed an increase to ~ 410 HV 0.1 in the fusion zone; however, due to segregation of Nb and formation of carbides, the precipitation of γ″ is not fully completed, and the yield strength (719 MPa) of the heat-treated welded joint is lower than the base material in aged condition.