PSI - Issue 60

ScienceDirect Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2023) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2023) 000–000 Available online at www.sciencedirect.com Procedia Structural Integrity 60 (2024) 93–114

www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

© 2024 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the ICONS 2023 Organizers Abstract AA 6061 is an age-hardenable aluminium alloy with 1wt% magnesium and 0.6wt% silicon as major alloying constituents and is used for manufacture of toroidal water tanks of earth storable liquid rocket engines of ISRO’s launch vehicles. These water tanks are used for storing water to generate steam in gas generator as well as for cooling various components of liquid rocket engine. As a part of the developmental efforts of a new source for fabrication of water tanks, a qualification test procedure was laid down, wherein a quarter portion of the water tank, namely the test article, is designed, fabricated and subjected to series of acceptance and qualification tests, including proof pressure test, cyclic pressure tests with intermediate non-destructive tests. These were finally followed by burst testing of the test article for conforming structural design margins and quality standards adopted for realizing the hardware. A burst test is a destructive test, performed to determine the overload capacity of the pressure vessels depicting margin of safety with respect to its mechanical strength limit. This work highlights the detailed manufacturing processes viz. forming, machining and welding including heat treatment of shells, metallurgical analysis carried out on the parent and weld specimens as well as results from proof pressure and pressure cyclic tests. Further, fractographic studies were carried out on the burst tested hardware, wherein specimens collected from different locations of the burst tested hardware were analyzed using optical scanning electron microscopy, to locate the origin of crack initiation and nature of the failure. © 2024 Rohan Nair, Harjit Singh, Harsh Agarwal, Aji Kumar A, Mankatiya Vittal Naik, Santhoshkumar R, Sureshkumar R, S.V.S. Narayana Murty. Published by ELSEVIER B.V. Abstract AA 6061 is an age-hardenable aluminium alloy with 1wt% magnesium and 0.6wt% silicon as major alloying constituents and is used for manufacture of toroidal water tanks of earth storable liquid rocket engines of ISRO’s launch vehicles. These water tanks are used for storing water to generate steam in gas generator as well as for cooling various components of liquid rocket engine. As a part of the developmental efforts of a new source for fabrication of water tanks, a qualification test procedure was laid down, wherein a quarter portion of the water tank, namely the test article, is designed, fabricated and subjected to series of acceptance and qualification tests, including proof pressure test, cyclic pressure tests with intermediate non-destructive tests. These were finally followed by burst testing of the test article for conforming structural design margins and quality standards adopted for realizing the hardware. A burst test is a destructive test, performed to determine the overload capacity of the pressure vessels depicting margin of safety with respect to its mechanical strength limit. This work highlights the detailed manufacturing processes viz. forming, machining and welding including heat treatment of shells, metallurgical analysis carried out on the parent and weld specimens as well as results from proof pressure and pressure cyclic tests. Further, fractographic studies were carried out on the burst tested hardware, wherein specimens collected from different locations of the burst tested hardware were analyzed using optical scanning electron microscopy, to locate the origin of crack initiation and nature of the failure. © 2024 Rohan Nair, Harjit Singh, Harsh Agarwal, Aji Kumar A, Mankatiya Vittal Naik, Santhoshkumar R, Sureshkumar R, S.V.S. Narayana Murty. Published by ELSEVIER B.V. Keywords: AA6061 aluminium alloy; burst test; proof pressure test; microstructure; fractography Third International Conference on Structural Integrity 2023 (ICONS 2023) Assessment on structural integrity of aluminium alloy AA6061 water tank used in satellite launch vehicles Rohan Nair a *, Harjit Singh a , Harsh Agarwal a , Aji Kumar A a , Mankatiya Vittal Naik a , Santhoshkumar R a , Sureshkumar R a , S.V.S.Narayana Murty a, a Liquid Propulsion Systems Centre, Indian Space Research Organisation, Valiamala, Thiruvananthapuram-695547, India Third International Conference on Structural Integrity 2023 (ICONS 2023) Assessment on structural integrity of aluminium alloy AA6061 water tank used in satellite launch vehicles Rohan Nair a *, Harjit Singh a , Harsh Agarwal a , Aji Kumar A a , Mankatiya Vittal Naik a , Santhoshkumar R a , Sureshkumar R a , S.V.S.Narayana Murty a, a Liquid Propulsion Systems Centre, Indian Space Research Organisation, Valiamala, Thiruvananthapuram-695547, India

Keywords: AA6061 aluminium alloy; burst test; proof pressure test; microstructure; fractography

* Rohan Nair. Tel.: 0471-256-8024; phone: +91-9967197903. E-mail address: rohan_nair@lpsc.gov.in

2452-3216 © 2024 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the ICONS 2023 Organizers 10.1016/j.prostr.2024.05.033 2452-3216© 2024 Rohan Nair, Harjit Singh, Harsh Agarwal, Aji Kumar A, Mankatiya Vittal Naik, Santhoshkumar R, Sureshkumar R, S.V.S. Narayana Murty. . Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the ICONS 2023 Organizers 2452-3216© 2024 Rohan Nair, Harjit Singh, Harsh Agarwal, Aji Kumar A, Mankatiya Vittal Naik, Santhoshkumar R, Sureshkumar R, S.V.S. Narayana Murty. . Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the ICONS 2023 Organizers * Rohan Nair. Tel.: 0471-256-8024; phone: +91-9967197903. E-mail address: rohan_nair@lpsc.gov.in