PSI - Issue 41

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Procedia Structural Integrity 41 (2022) 430–438

2nd Mediterranean Conference on Fracture and Structural Integrity Influence of short-term post welding heat treatments on corrosion resistance of UNS N06625 nickel-chromium-molybdenum alloy 2nd Mediterranean Conference on Fracture and Structural Integrity Influence of short-term post welding heat treatments on corrosion resistance of UNS N06625 nickel-chromium-molybdenum alloy

Paolo Ferro a *, Alberto Fabrizi a , Franco Bonollo a , Filippo Berto b a University of Padova, Department of Engineering and Management, Stradella S. Nicola 3, 36100 Vicenza, Italy b NTNU, Department of Engineering Design and Materials, Trondheim, Norway Paolo Ferro a *, Alberto Fabrizi a , Franco Bonollo a , Filippo Berto b a University of Padova, Department of Engineering and Ma gement, Stradella S. Nicola 3, 36100 Vicenza, Italy b NTNU, Department of Engineering Design and Materials, Trondheim, Norway

© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the MedFract2Guest Editors. Click here and insert your abstract text. © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Two hort-term inducti n PWHTs (holding tim , 20 mi ) at 980 and 1050 °C were investigated and correlated with b th microstructural and corrosion res sta ce of the welded joints, according to St ndard ASTM G28 A. Inter-dendritic segregation of key alloy ele en s have b en identified as the main cause of the corrosive tack initiati n. The temperature of 1050 °C was found to be the most effective to restore the corrosion resistance of the investigated welded joint. Click here and insert your abstract text. © 2022 The Authors. Published by ELSEVIER B.V. This is an ope acces article under CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Abstract UNS N06625, commonly known as Inconel 625, is a Nickel-Chromium-Molybdenum alloy with a very good corrosion resistance to a wide range of corrosive media and therefore the favorable choice for sea water applications. However, fusion welding operations may compromise its optimal corrosion resistance if a corrective post welding heat treatment (PWHT) is not carried out. In this scenario, optimum induction PWHT parameters are not yet consolidated so that there are still uncertainties that need to be investigated by proper experiments. Two short-term induction PWHTs (holding time, 20 min) at 980 and 1050 °C were investigated and correlated with both microstructural and corrosion resistance of the welded joints, according to Standard ASTM G28 A. Inter-dendritic segregations of key alloy elements have been identified as the main cause of the corrosive attack initiation. The temperature of 1050 °C was found to be the most effective to restore the corrosion resistance of the investigated welded joint. Abstract UNS N06625, commonly known as Inconel 625, is a Nickel-Chromium-Molybdenum alloy w th a very g od co rosion resistance to a wide range f corrosive media nd theref re the favorable choi e for sea ater applications. However, fusion weld ng perations may compromise its optimal corrosion esistance if a corrective post welding heat tre tment (PWHT) is not carri out. In thi scenario, optimum induction PWHT parameters are not yet consolidated so that there are still uncertainties that need to be investigated by proper experiments.

Peer-review under responsibility of the MedFract2Guest Editors. Keywords: Nickel-based alloy, welding, corrossion resistance, microstructure P er-review under r sponsibility of the MedFract2Gu st Edito s. Keywords: Nickel-based alloy, welding, corrossion resistance, microstructure

* Corresponding author. E-mail address: paolo.ferro@unipd.it * Corresponding uthor. E-mail address: paolo.ferro@unipd.it

2452-3216 © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license ( https://creativecommons.org/licenses/by-nc-nd/4.0 ) Peer-review under responsibility of the MedFract2Guest Editors. 2452-3216 © 2022 The Authors. Published by ELSEVIER B.V. This is an ope acces article under CC BY-NC-ND license ( https://creativecommons.org/licenses/by-nc-nd/4.0 )

Peer-review under responsibility of the MedFract2Guest Editors.

2452-3216 © 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the MedFract2Guest Editors. 10.1016/j.prostr.2022.05.049