PSI - Issue 60

Rohan Nair et al. / Procedia Structural Integrity 60 (2024) 93–114 Rohan Nair / Structural Integrity Procedia 00 (2023) 000–000

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IC rings, flange, adaptor I, II& III were realized from forgings in AA6061-T652 condition. Initially rough machining was carried out with allowances all around. In order to relieve the stresses generated during rough machining, the machined job was kept aside (natural ageing) for 14 days. Fig. 6 describes the manufacturing sequence of IC rings, flange and adaptor.

Natural ageing (14 days)

AA 6061 T652 forging

Rough Machining

Finish Machining

Fig. 6: Fabrication flow chart of IC rings, flange and adaptor

2.1.3. Anti-slosh baffles: Anti-slosh baffles were formed from AA6061 2mm thick sheets in T0 condition and were finally heat treated to T6 condition. The machining of the holes was carried out in this formed and HT condition; however, no machining was carried out in the baffle riveted in the test article since it is for qualification purpose (ground use). Welding: One shell segment was formed from two half shells by long-seam welding. The IC rings and flanges were welded to shells by cir-seam welding. The adaptors were welded on to the formed toroid shells. Semi automatic TIG welding was used for fabrication of test article. The movement of job was automated but the torch movement and filler wire feed were carried out manually. The Welding Procedure Specification (WPS) [7] and parameters were established for long seam and cir-seam welding with joint details as given in table-1. Table. 1: Welding Procedure Specification and weld parameters for long-seam and cir-seam welding. 2.1.4.

Long seam weld

Cir seam weld

Joint Details Square Butt ER 4043 Dia. 2.4mm Stainless steel

Joint type

Square Butt ER 4043 Dia. 2.4mm Stainless steel

Filler wire and size

Backing materials

Base metal specification

Material Thickness

AA 6061-T6

AA 6061-T6 & Forging AA 6061-T652

2mm

2mm

Gas Flow details Argon + Helium 80:20

Gas type (% composition)

Argon + Helium 80:20

Shielding/Trailing/Backing (lpm)

Yes/No/No 12-15 lpm Dia. 10mm

Yes/No/No 12-15 lpm Dia. 10mm

Gas Cup size

Electrical characteristics

EWP Pure tungsten Dia. 3.2mm

EWP Pure tungsten Dia. 3.2mm

Electrode type and size

Amp. Range (I) Volt range (V)

100 + 20

110 + 10 15.5 + 1.5

16 + 2 30 + 5

Travel speed range

28 + 2