PSI - Issue 14

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Procedia Structural Integrity 14 (2019) 930–936

2nd International Conference on Structural Integrity and Exhibition 2018 Effect of hydrogen on short crack propagation in SA508 Grade 3 Class I low alloy steel under cyclic loading Rajwinder Singh a , Amanjot Singh a , Pawan K. Singh b , Dhiraj K. Mahajan a * a Ropar Mechanics of Materials Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab, India, 140001 b Reactor Safety Division, Bhabha Atomic Research Centre, Mumbai, India, 400085 Abstract The effect of hydrogen on short crack propagation under cyclic loading in SA508 Grade 3 Class I low alloy steel is investigated. This low alloy steel is used in manufacturing of pressure vessel installed in Indian nuclear power plants. During operation these pressure vessels are subjected to continuous supply of pressurized hot water at 600 K and hence are susceptible to hydrogen embrittlement. In past, research has been conducted on the effect of hydrogen embrittlement on long fatigue crack propagation in this material but, the mechanistic understanding and correlation of hydrogen embrittlement with microstructural features in the material can be understood well by studying the effect of hydrogen embrittlement on short fatigue crack propagation. Short fatigue cracks are of the order of 10 µm to 1 mm and unlike long cracks these short cracks strongly interact with the microstructural features in the material such as grain/phase boundaries. The effect of hydrogen embrittlement on short crack propagation is studied by artificial hydrogen charging of the material through electrochemical process. The single edge notch tension (SENT) specimens with an initial notch of the order of 85 to 90 µm are used to study the short crack propagation. The short cracks in hydrogen charged samples initiated from the notch at lower number of loading cycles as compared to the uncharged notched samples for the same value of applied stress range ( ∆ ). After initiation, the short fatigue crack in hydrogen charged samples propagated at higher rate as compared to uncharged samples. This dissimilarity in crack propagation behavior is due to the difference in the interaction of short fatigue crack with the microstructural features for a hydrogen charged and uncharged samples. © 2018 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/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 2nd International Conference on Structural Integrity and Exhibition 2018 Effect of hydrogen on short crack propagation in SA508 Grade 3 Class I low alloy steel under cyclic loading Rajwinder Singh a , Amanjot Singh a , Pawan K. Singh b , Dhiraj K. Mahajan a * a Ropar Mechanics of Materials Laboratory, Department of Mechan cal Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab, India, 140001 b Reactor Safety Division, Bhabha Atomic Research Centre, Mumbai, India, 400085 Abstract e effect of hydrogen on short crack propa ation under cyclic loading in SA508 Grade 3 Class I low alloy steel is investigat d. Thi low alloy teel i us d in manufact ring of ressure v sel installed in Indian nucle r power pl nts. During operation these pressure v ssels are subjected to conti uous supply of pr ssurized hot water at 600 K a d hence are s s eptible to hydr ge embrittl ment. In past, r se rch has be n conducted on th effect it l t on long fatigue rack propagat on in this m teri l ut, the mechanistic understanding and correlation f hydrogen e brit lement with microstructu al features in the material c n be unders ood w ll by studying the effect of hydrogen emb ittlement on short f tigue crack propaga ion. Short fatigue cracks are of the order of 10 µm to 1 mm and unlike long cracks these s ort cracks st ongly interact with the microstructural features in the m terial such as grain/phase boundaries. The eff t f ydrogen embrittlement on short cra k propagation is studied by art fici l hydrogen c arging f the material through electrochemical process. The single edge notch tension (SENT) specim s with an initia notch of the rder of 85 to 90 µm a e sed to study the short crack propagation. T short cracks in hydrogen cha ged ples initiated from the notch at lower number f loading cycles as compared t the uncharged notched sampl s for the same v lue of pplied stress range ( ∆ ). After in tiation, the short fatigue cr ck in hydr gen charged samples propagated at higher rate as c mpared to uncharged samples. This dissimilari y in crack propagation behavior is due to the differ nce in the interaction of short fatigue crack with the microstructural features for a hydrogen charged and uncharged samples. © 2018 The Authors. Published by Elsevier B.V. This is a open access article under the CC BY-NC-ND lic nse (https://creat vecommons.org/licenses/by- c-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. © 2019 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/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers.

* Corresponding author. Tel.: +91-7814252244; fax: +0-000-000-0000 . E-mail address: dhiraj.mahajan@iitrpr.ac.in * Correspon ing author. Tel.: +91-7814252244; fax: +0-000-000-0000 . E-mail address: dhiraj.mahajan@iitrpr.ac.in

2452-3216 © 2018 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/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. This is a open access article und r the CC BY-NC-ND lic nse (https://creat vecommons.org/licenses/by- c-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers.

2452-3216  2019 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/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 10.1016/j.prostr.2019.07.073