PSI - Issue 17

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000

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Procedia Structural Integrity 17 (2019) 440–447

ICSI 2019 The 3rd International Conference on Structural Integrity Environmentally-Assisted Cracking of Type 316L Austenitic Stainless Steel in Low Pressure Hydrogen Steam Environments Jaromír Janoušek a, b *, Fabio Scenini c , Liberato Volpe c , Anna Hojná b , M. Grace Burke c a Research Centre Rez, Hlavní 130, 250 68 Husinec- Řež, Czech Republic b University of West Bohemia, Department of Material Science and Technology, Univerzitní 22, 306 14 Plzeň , Czech Republic c The University of Manchester, Material Performance Centre, Manchester, United Kingdom ICSI 2019 The 3rd International Conference on Structural Integrity Environmentally-Assisted Cracking of Type 316L Austenitic Stainless Steel in Low Pressure Hydrogen Steam Environments Jaromír Janoušek a, b *, Fabio Scenini c , Liberato Volpe c , Anna Hojná b , M. Grace Burke c a Research C re Rez, Hl vní 130, 250 68 Husinec- Řež, Czech Republic b University of West Bohemia, Department of Material Science and Technology, Univerzi ní 22, 306 14 Plzeň , Czech Republic c The University of Manchester, Material Performance Centre, Manchester, United Kingdom A low pressure, superheated hydrogen-steam system has been used to accelerate the oxidation kinetics while keeping the electrochemical conditions similar to those of the primary water in a pressurized water reactor. The initiation has been investigated using a Constant Extension Rate Tensile (CERT) test. Tests were performed on flat tapered specimens made from Type 316L austenitic stainless steel with strain rates of 2×10 -6 and 2×10 -8 ms -1 at room temperature and at an elevated temperature of 350 °C. R = 1/6 was chosen as a more oxidizing environment and R = 6 was selected as a more reducing environment, where the parameter R represents the ratio between the oxygen partial pressure at the Ni/NiO transition and the oxygen partial pressure. Different exposures (1 day and 5 days) prior to loading were investigated post-test evaluation by scanning electron microscopy. A low pressure, superheated hydr gen-steam system has bee used to accelerate the xidatio kinetics while keepin the electrochemic l conditions similar to those of the primary water in a ressurized water reactor. The initiation has been investigated using a Constant Extension Rate Tensile (CERT) test. Tests were perf rm d on flat tapered specimens made from Type 316L austenitic stainless steel with strain rates of 2×10 -6 and 2×10 -8 ms -1 at room temperature and at an elevated temperature of 350 °C. = 1/6 was chosen as a more oxidizing environment and R = 6 was selected as a more reducing environment, wh re the parameter R represents the ratio between the xygen partial pressure at the Ni/NiO transition and the oxygen partial pressure. Different exposures (1 day and 5 days) prior to loading were investigated post-test evaluation by scanning electron microscopy. Abstract Abstract

© 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers.

Keywords: Environmentally Assisted Cracking; hydrogenated steam; oxidation; austenitic steel Keywords: Environmentally Assisted Cracking; hydrogenated steam; oxidation; austenitic steel

1. Introduction 1. Introduction

Environmentally-assisted cracking (EAC) is, according to Raja and Shoji (2011), the dominant issue in determining the reliability of most commercial equipment and applications that are controlled by the interactions between structural materials, cooling environments and operating stresses. Primary water stress corrosion cracking (SCC) is a form of EAC that can occur in essentially pure hydrogenated water at elevated temperatures. Hydrogen gas promotes EAC in Environmentally-assisted cracking (EAC) is, according to Raja and Shoji (2011), the dominant issue in determining the reliability of most com ercial equipment and applications that are controlled by the interactions between structural materials, cooling environments and operating stresses. Primary water stress corrosion cracking (SCC) is a form of EAC that can occur in essentially pure hydrogenated water at elevated temperatures. Hydrogen gas promotes EAC in

* Corresponding author. Tel.: +420720737082. E-mail address: jas@cvrez.cz * Correspon ing author. T l.: +420720737082. E-mail address: jas@cvrez.cz

2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. 2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers.

2452-3216  2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. 10.1016/j.prostr.2019.08.058