Microstructure and hardness studies of the electron beam welded zone of Hastelloy C-276

• Published in: Journal of alloys and compounds 2005-03, Vol.390 (1), p.88-93
• Main Authors: Ahmad, M., Akhter, J.I., Akhtar, M., Iqbal, M., Ahmed, E., Choudhry, M.A.
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Electron beam welding; Exact sciences and technology; Hastelloy C-276; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Micro-eutectoids; Molten zone; Physics; Precipitation; Scanning electron microscopy; Tribology and hardness; X-ray diffraction
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2004.08.031

Electron beam welding (EBW) technique is becoming popular in nuclear, chemical and aerospace industries due to its high penetration depth and fast cooling rate. Samples of Hastelloy C-276 have been welded by electron beam (EB). A scanning electron microscope (SEM) having the attachment of an energy dispersive system (EDS) has been employed to study the resulting microstructure and micro-eutectic phases. The microstructure of the molten zone (MZ) is found to be of fine lamellar type. The hardness of the MZ is found to be 35% higher compared to as-received alloy. The micro-eutectoids are rich in Mo and W. The X-ray diffraction patterns of the MZ show shifting of peaks towards higher angle compared to the diffraction pattern of the as-received alloy. Broadening of the peaks is also observed in the diffraction pattern of the MZ. Formation of the μ-phase was observed in the MZ after a tempering treatment at 950 °C.