Issue 50

L. Romanin et al., Frattura ed Integrità Strutturale, 50 (2019) 251-263; DOI: 10.3221/IGF-ESIS.50.21 251 Focussed on IGF25 – Fracture and Structural Integrity International Conference 2019 A metallurgical and thermal analysis of Inconel 625 electron-beam welded joints L. Romanin, P. Ferro, A. Fabrizi University of Padova, Italy luca.romanin@phd.unipd.it paolo.ferro@unipd.it , https://orcid.org/0000-0001-8682-3486 alberto.fabrizi@unipd.it F. Berto University of Trondheim (NTNU), Norway filippo.berto@ntnu.no , https://orcid.org/0000-0002-4207-0109 A BSTRACT . Inconel 625 is a nickel-based superalloy that finds application in many industrial sectors thanks to its high strength, excellent fabricability, and outstanding corrosion resistance. It is characterized by a good weldability and often used in the as-welded conditions. In the following, a metallurgical and thermal analysis of Inconel 625 Electron- Beam welded joints is described. The thermal analysis was supported by a numerical model that uses a superimposition of a spherical and a conical shape heat source with Gaussian power density distribution in order to reproduce the nail-shape of the fusion zone. The heat source parameters were calibrated by using experimental data coming from metallurgical observations and temperature measurements. Numerical and experimental results were found in good agreement. K EYWORDS . Welding; Inconel 625; Thermal Analysis; Numerical Modelling; Microstructure. Citation: Romanin, L., Ferro, P., Fabrizi, A., Berto, F., A metallurgical and thermal analysis of Inconel 625 electron-beam welded joints, Frattura ed Integrità Strutturale, 50 (2019) 251-263. Received: 27.07.2019 Accepted: 17.08.2019 Published: 01.10.2019 Copyright: © 2019 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION ickel-base superalloys for aerospace and industrial applications are of great interest in the materials research field. Their creep and oxidation resistance properties make them the base material for aero-engine components in hot sections, such as turbine discs, blades and casings. In such applications, the possibility to repair or assemble different parts by welding is a fundamental task for the design and industrialization of these products. Therefore, studies related to the weldability of this kind of material are of primary importance in order to obtain sound welds. Their hot cracking sensitivity, arising from a synergy of phenomena such as wide solidification temperature interval, chemical N