Improvement in the microstructural properties of super duplex and austenitic stainless steel dissimilar joints by incorporating Ni-based austenitic interlayer

Influence of inconel interlayer on microstructural, mechanical and electrochemical characteristics in single-pass ATIG welding of dissimilar austenitic and duplex stainless steel

“…The utilization of SiO 2 flux resulted in the narrow weld bead primarily because of the prevalence of arc convergence, while TiO 2 flux contributed to the highest penetration depth by favouring the reversal of Marangoni convection [1,[20][21][22]. Consequently, in the previous work, enhanced weld bead cross-section by augmenting penetration depth and reducing the width of weld bead was noticed [7,23,24]. Table 2 lists the ATIG welding process parameters.…”

“…However, in interlayer-based case no sensitization was noticed. These zero sensitization of interlayer-based weldment could be due to the fully austenitic microstructure in the WZ [7,56], also, FCC phase is more thermodynamically stable.…”

“…Pre-and post-heat treatments, rapid welding speeds, and other procedures are usually necessary to overcome these problems. However, ATIG can reduce grain coarsening in the HAZ and the weld metal due to the unique characteristics of the ATIG process [7]. The activated flux used in the TIG helps to refine the weld grain structure, resulting in improved toughness and ductility compared to conventional fusion welding methods [8].…”

“…The WZ of weldment without interlayer displayed a fully martensitic structure, however, the weldment Inconel 600 exhibited with a completely austenitic structure while the Incoloy 800 interlayer exhibited partial austenitic structure. Fande et al [7] studied the impact of Inconel 625 interlayer on dissimilar welding of super-DSS S32760 and 202 ASS using TIG and ATIG welding technique and concluded that the ATIG is efficient as compared to TIG welding.…”

Enhancing microstructure and mechanical properties of dissimilar TIG welded duplex 2205 and Ni-based inconel 718 superalloy through post weld heat treatment

“…Typically, the grain boundaries of the superalloy Inconel 718 contain carbides or carbonitrides [23]. However, the DSS 2205 revealed a mixed microstructure made up of ferrite and austenite, roughly equal volumetric fraction of ferrite and austenite [24]. Ferrite, the dark phase, contributes to strength while austenite, the light phase, enhances toughness and corrosion resistance.…”