Study on hydrogen embrittlement and dynamic strain ageing on low-alloy reactor pressure vessel steels

JOURNAL OF NUCLEAR MATERIALS

卷:556

Article

Rao, G. S.^1,2  Yagodzinskyy, Y.³  Que, Z.^1,4  Spatig, P.¹  Seifert, H. P.¹ 

[1] Paul Scherrer Inst, Lab Nucl Mat, CH-5232 Villigen, Switzerland

[2] CSIR, Natl Met Lab, Jamshedpur 831007, Bihar, India

[3] Aalto Univ, Sch Engn, Espoo 02150, Finland

[4] VTT Tech Res Ctr Finland, Kivimiehentie 3, FI-02044 Espoo, Finland

关键词: Hydrogen embrittlement;    Dynamic strain ageing;    Thermal desorption spectroscopy;    Low-alloy steel;    Reactor pressure vessel;   

DOI  :  10.1016/j.jnucmat.2021.153161

来源: Elsevier

【 摘 要 】

Tensile tests in air with hydrogen pre-charged smooth specimens and slow strain rate tests with smooth and notched specimens in hydrogenated high-temperature water (HTW) at elevated temperatures (250-288 degrees C) on low-alloy reactor pressure vessel (RPV) steels revealed a softening in strength and a pronounced reduction in ductility, where the magnitude of hydrogen embrittlement (HE) increased with the dynamic strain ageing (DSA) susceptibility of the RPV steels. In hydrogen pre-charged specimens and in hydrogenated HTW, shear dominated transgranular fracture by microvoid coalescence with increasing amounts of macrovoids, quasi-cleavage regions and secondary cracking were observed. Thermal desorption spectroscopy showed an increase in the concentration of trapped hydrogen in high binding energy traps (vacancies & voids) induced by straining in DSA regime. The observed hydrogen effects on fracture behaviour is a consequence of plasticity localization resulting from the interaction between DSA and hydrogen. HESIV and HELP are the dominant HE mechanisms. (C) 2021 The Author(s). Published by Elsevier B.V.

【 授权许可】

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