[Background] Inconel 617 alloy exhibits a superior combination of high-temperature strength, corrosion resistance, and oxidation resistance, showing broad application prospects in nuclear pressure vessels, industrial gas turbines, and A-USC coal-fired steam units. The lack of systematic development of welding consumables with excellent applicability, combined with ill-defined processing windows for various welding methods, constitutes one of the critical technical bottlenecks restricting its widespread industrial application.

[Objective] This paper systematically addresses the weldability characteristics of Inconel 617, reviewing the research progress on its primary welding processes, welding consumables, and PWHT, with the aim of providing reference for future in-depth research and engineering applications. 

[Analysis] Due to its high alloying element content, Inconel 617 tends to form a high volume fraction of liquid films during the welding thermal cycle, rendering it highly susceptible to solidification cracking and liquation cracking. Consequently, processing parameters such as welding heat input and cooling rate exert a profound influence on the mechanical properties of the joints. Among arc welding processes, TIG welding produces joint properties superior to other arc processes owing to its low heat input and effective metallurgical shielding; furthermore, multi-pulse NG-TIG welding have expanded its applicability across varying plate thicknesses. MIG welding provides high efficiency and degree of automation, but its joint performance is slightly inferior to TIG due to higher heat input—though CMT welding achieves excellent joint quality. SMAW suffers the most severe loss in impact toughness among arc processes, as insufficient metallurgical shielding by the electrode flux coating leads to high inclusion densities in the weld metal. Compared to conventional arc welding, LBW and LHW offer higher power densities and superior heat input control, generally yielding superior overall joint performance relative to TIG. In diffusion bonding, the core issue of oxide and carbide inclusions remains unresolved, resulting in poor metallurgical bonding and severe degradation of ductility and toughness. Regarding welding consumables, solid wires for Inconel 617 have reached industrial maturity, whereas flux-coated electrodes and diffusion bonding interlayers still require compositional optimization to mitigate oxide inclusion formation during processing. Regarding PWHT, Inconel 617 exhibits an excellent solid-solution strengthening response; thus, its welded joints are generally considered suitable for service in the as-welded condition, though stabilization treatment or full solution annealing may be applied when necessary. 

[Conclusion] Taken together, heat input and metallurgical shielding performance represent the central issues influencing the properties of Inconel 617 joints. NG-TIG welding, CMT welding, and laser-arc hybrid welding yield superior joint performance, serving as the most promising joining processes for Inconel 617 applications.