Effect of Post-Welding Treatment on Corrosion Behavior of Laser and Gas Tungsten Arc-Welded (Fe50Mn30Co10Cr10)99C1 Interstitial High-Entropy Alloy

• Published in: JOM (1989) Vol. 75; no. 12; pp. 5568 - 5580
• Main Authors: Yebaji, Sushil, Sudeep Kumar, T., Verma, Ayush, Natu, H., Gowtam, D. S., Shanmugasundaram, T.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.12.2023; Springer Nature B.V
• Subjects: Alloys; Base metal; Chemistry/Food Science; Corrosion effects; Corrosion potential; Corrosion resistance; Corrosion tests; Deformation; Ductility; Earth Sciences; Engineering; Entropy; Environment; Face centered cubic lattice; Friction stir welding; Gas tungsten arc welding; Heat treatment; High entropy alloys; Investigations; Laser beam welding; Lasers; Microstructures and Mechanical Behavior of High-entropy Materials; Morphology; Photoelectrons; Physics; X ray photoelectron spectroscopy
• ISSN: 1047-4838; 1543-1851
• DOI: 10.1007/s11837-023-06210-w

The influence of post-welding heat treatment on the surface and corrosion properties of the interstitial high-entropy alloy (Fe 50 Mn 30 Cr 10 Co 10 ) 99 C 1 has been examined using gas tungsten arc welding (GTAW) and laser welding. The as-welded and post-weld heat-treated samples were characterized using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Face-centered cubic (FCC) and hexagonal close-packed (HCP) structures were present in the base metal. There was no change in the phases after welding and post-heat treatment. After laser and GTAW, a small reduction in hardness (25 HV) was noticed. Following both laser and GTAW processes, the base metal's corrosion resistance dropped. However, heat treatment applied after the weld brought the resistance back to almost base metal levels (0.002 mm/year). The development of Mn oxides on the surface, which minimizes the micro-segregation of Cr and generates a uniform Cr oxides layer, is primarily responsible for the increased corrosion resistance in the post-welded samples. This layer also exhibits superior passivation and corrosion resistance. The study clearly demonstrates that, in Mn-containing high-entropy alloys, it is important to suppress elemental Mn content on the surface for improved corrosion resistance.