Evaluation of Microstructure, and Mechanical Properties of Superalloy 59 and 904L Dissimilar welds using Hot Wire Turbo TIG

• Published in: Archives of metallurgy and materials Vol. 70; no. 2; pp. 803 - 817
• Main Authors: Muthukumaran, N., Arulmurugan, B., Sureshkumar, R., Bharathikanna, R.
• Format: Journal Article
• Language: English
• Published: Warsaw Polish Academy of Sciences 25.06.2025
• Subjects: 904l; Capillarity; Cryogenic treatment; dissimilar welding; Ductile fracture; Fracture toughness; Gas tungsten arc welding; Hardness tests; Heat affected zone; Heat treating; hot wire turbo tig; Impact strength; Impact tests; Marangoni convection; Mechanical properties; Microstructural analysis; Microstructure; Structural reliability; superalloy 59; Superalloys; Tensile strength; Welded joints; Welding wire; Weldments; Wire
• ISSN: 2300-1909; 1733-3490; 2300-1909
• DOI: 10.24425/amm.2025.153483

This research involves the dissimilar welding of a novel combination of superalloy 59 and 904L using Hot Wire Turbo TIG welding (HWTT) with ERNiCrMo-13 filler wire. Macroscopic examination revealed defect-free welds with optimized geometry and minimal heat-affected zone. The bead geometry, influenced by capillary action and the Marangoni effect, exhibited a 7 mm crest width, 5.5 mm center width, and 2.6 mm depth. Microstructural analysis through FESEM and EDS revealed a substantial 32.06% Mo-enriched secondary phase in the fusion zone, vital for structural reliability and enhancing weldment mechanical properties. Hardness testing revealed 15% higher values in the weld joint compared to base metals. Cryogenic treatment enhanced the weldment tensile strength by up to 10%, with deep cryogenic treatment (DCT) surpassing as-welded samples by 9.5%. Tensile and impact tests, along with fractography images, revealed microstructure-influenced ductile fractures. Charpy impact toughness of the weld fusion zone, at 89 J, showcases favorable properties, 2% lower than alloy 59 but 11.2% higher than 904L, attributed to DCT.